Dodge Dakota Driveline Rebuild and Frame Repair

[rusticretreater]

Heyo,

My 2000 Dodge Dakota had gotten into pretty bad shape due to all the moving, hauling and general abuse I heap upon it.  Only 164,000 miles, but they have been working miles. My 5-speed transmission had lost its synchro and the trans would pop out of first gear.  The bearings were gone in the differential and it was howling. My throwout bearing seized finally forcing me to install all the parts I have been collecting and of course ordering more items.

Also, the frame has rusted to the point where the state inspection guy said don't bring it in again until its fixed.  Dodge used a riveted together frame behind the cab which allowed them to offer three different cab sizes and two different bed sizes by adjusting the length of the add-on frame parts.  The joint rusts horribly and requires disassembly, cutting out the rust and welding in new metal to repair it.

Most guys would throw in the towel but not me.  Also, I hate buying vehicles and paying taxes, title and registration, etc. etc.  So here is the tale of my efforts to bring the Dakota back from the brink of the junkyard abyss.

[rusticretreater]

As I needed to do some work with the truck prior to taking the bed off and disassembling the entire rear of the truck to fix the frame, I repaired the driveline first.

I purchased a nice pilot bearing setup from Timken, a new Luk flywheel, a nifty kevlar clutch and pressure plate from Spec Clutches and a rebuilt NV3500 5-speed transmission. I also procured new U-joints for the driveshaft and a Yukon gear differential rebuild kit which also included new axle bearings and seals.



 
New Luk Flywheel, bolts and pilot bearing.



 
New Venture 3500 5-speed transmission ready for install



 
New throwout bearing installed on yoke.  Clutch operated by hydraulic master/slave cylinder combo.




New Spec kevlar clutch and pressure plate.  

[rusticretreater]

Shifter fun:

My Dakota is a 2000 model and the rebuilt trans that I was able to pick up for $600(way below market price) was a 2001-2004 version.  The bellhousing pattern is the same but there are a few changes.  In 2001, Dodge changed the interior of the pickup and in doing so raised the socket of the top loaded shifter on the transmission 1/2".  No biggie you would think.  Well, don't think.

They also changed the shifter shape.  My 2000 shifter would not work with this transmission as it was not tall enough to take up the 1/2".  Also, the 2001-2004 shifter that fits the transmission does not work in the 2000 Dakota, hitting the dashboard when shifting.

The solution is to buy a shifter for a Chevrolet PU that uses the same NV3500 transmission.  The new shifter is disassembled and the metal lever part from the Dakota shifter is used to reassemble it.  The nylon bushings are the same for both shifters, so you end up with a new 2000 Dakota shifter that will work with the 2001-2004 transmission.  I got that solution from one of the forums.  The internet is pretty darn cool.

[bigblockyeti]

It certainly looks like you're diving in with both feet!  I had a lease '98 that was driven like a leased vehicle, I got most of the goody out of that truck in not very much time, not a bunch of miles either.  The one thing I remember is the AX15 transmission shifted great when it was brand new and after ~30K miles and three years it shifted like a bucket of bolts with most of the syncros only sort of doing their job.  The 2002 I bought in late 2001 was a better truck, save for the center console instead of a 40/20/40 bench like the '98 had.  They were both regular cab, 6.5' bed 2wd manual trucks, plain, simple and easy to work on.  The NV3500 in the '02 shifted poorly when new, it had to be broken in then around 10K or so, it really felt nice and never changed as long as I owned it.  Rust really started making progress on it by 2015 and I ended up selling it in 2017 running poorly (a few emissions related problems) for only $1500.  The irony being the guy buying it was looking for a truck to dissect to rebuild his truck but then decided mine was in better shape so it would receive necessary parts from his truck instead.  I never had to drop the tranny but I only put ~80K on it in just under 16 years.  The frame was fine but more and more of the sheet metal was becoming perforated as it aged.  Major repairs really weren't, I had to do both rear brake lines on the axle, the hard line running to the rear axle, replaced both front calipers, both front soft lines, a couple idler pulleys, spring hangers, rear pinion seal, both rear axle seals (only one was leaking) and that's it other than preventative maintenance items.  It needed more power and more speed from the non-balanced 90° V6 but it was a very old design that still did fairly well if not necessarily efficient for the power it offered.  Sometimes I miss it, most I don't.  It served me well and I suspect at least some parts somewhere might still be on the road keeping someone headed from point A to point B.

Good luck with your repairs and I hope your able to double the mileage with all those new parts!

[Don P]

Thanks for taking us along, I don't even begin to understand what I'm looking at for a clutch  ???.

[rusticretreater]

Not what I exSPECted:

Well, my fancy SPEC kevlar clutch and pressure plate setup didn't work.  After finishing the transmission swap I tried to take it for the ol' test drive.

Had to push the pedal to the floor to feel the clutch release.  Tried to put it in gear. No go.  Reverse?  Just grinds.  Shut off the engine. run through the gears and put it in first. No problem.  Start the truck, let out the clutch an inch and the truck goes. Shifting is brutally hard.  Will not go into any gear at a stop except third.

So I check the clutch hydraulics and find nothing wrong.  The previous clutch was working when I took things apart and the Master/slave cylinder setup was replaced 2 years ago.  Then I pulled the transmission again.  I checked everything for proper installation.  I compared the two transmissions, measured the distances inside the bellhousing and found nothing wrong.

Of course the SPEC tech support guy said they haven't had any problems with Dodge clutch installations.  It was clear to me that there was still friction being applied to the clutch disc when the pedal was depressed keeping the syncros from being able to align things in the transmission and allowing it to be shifted.

So I devised a test.  I assembled the stock flywheel, the kevlar disc and the stock pressure plate together and put them on my hydraulic press.  I put a bushing driver disc on the pressure plate and applied force until I could not move the disc.  Then I took a measurement from the top of the press frame to the top of the moving bar of the press.  I also setup a dial indicator to read how much the pressure plate rose during the test.

I applied pressure until I was able to get a .025 feeler gauge in between the pressure plate and the clutch disc.  I then retook the measurements from the press frame to see the distance it took to raise the pressure plate.  The same test was done using the SPEC pressure plate.

I found that it took the stock setup 3/8ths of an inch compression and the SPEC setup 5/8ths of an inch to move the pressure plate the same amount. A quarter of inch is no big deal until you consider the linkage ratio.  The yoke clutch system used is a 2:1 ratio which means it took SPEC setup 1 1/4" of slave cylinder piston extension to work the clutch.  The stock system needed only 3/4".  A difference of 1/2".  I don't know how much pedal travel was required but I guessed it was more than 3:1.

[Southside]

Yea - that's exactly what I would have done to figure it out, you beat me to it, yup - what he said.  :D I am in the same boat as Don when it comes to the whole clutch thing but enjoying the progress and explanations. 

[rusticretreater]

So I ordered a Centerforce setup.  Not kevlar, but organic/carbon fiber.  First thing I did when I got it was to measure it like I did the other two setups.  Here are the results:



 

So the Centerforce setup fell in between the two other setups when tested with the kevlar disc.  But with its own disc, it needed 3/8ths of an inch less movement.  So I installed the Centerforce setup and sent the SPEC setup back.  I am still agitating for a refund.  Clutch works fine and the pedal is an inch off the floor and no issues shifting the rebuilt transmission.


 

[rusticretreater]

Next thing to fix is the howling differential.  My Dakota is a 4WD truck and therefore has the Chrysler 9.25 differential and something called Trac-loc which is a type of posi-traction.

After taking the cover off and draining the fluid, I found a couple of pieces of the belleville tensioning washers in the bottom of the case. After disassembly, I found the outer pinion bearing(where the driveshaft connects) and its race to be torn up. This was the source of the howling sound.

The way the differential comes apart is that you remove the rear tires and brake drums, remove the bolt holding the center pin in the differential, remove the center pin, push in on each axle which makes the retaining clip pop out of its recess and fall to the bottom of the case.  You then pull each axle out of the differential.  I use the brake drums as stands for the axles so they are not rolling around on the floor.

In most differentials, clearance and backlash is set by inserting shims at either end of the differential. Its a pretty tight fit.  There are tools to actually spread the differential housing wider so you can get the shims in.  Chrysler came up with something different.  A long tool is inserted into the axle tube and engages an adjuster on each side.  You just simply unscrew it a bit to get some freeplay.  You can then remove the holding brackets and take the carrier unit out of the differential.



 
The inside of the differential case.  In the center, the new outer pinion bearing is in place with a new seal. The two outer circles are the pinion bearing races. On the right you can see the adjuster tool sticking out of the adjuster.  The black thing at the top left is a breather port that also has a sensor on it.  It reads axle speed for the computer. It had a pretty good amount of metal sticking to it.

[rusticretreater]

The Trac-loc set up uses a clutch pack on each side of the unit to constantly apply power to the axles while the truck is moving.  The pack is a series of clutch disks and metal plates pressed together by a belleville washer.  A belleville washer is a concave shaped washer that flattens out under load.  The more it flattens, the tighter the clutch pack grips.  As you go around turns, the axles tend to pull outward on the differential, pulling the washer flatter and increasing the power transfer to the axle.  It works under the same principle as the manual clutch for the transmission.



 

Rebuilding these units takes some finesse and also some force.  The ring gear is removed to gain clearance to work.  The rebuild kit comes with new bolts for the ring gear as they are special. Then each clutch pack is compressed to get clearance in the center of the unit.  This allows the spider gears, little gears inside the unit that help the axles rotate at different speeds when you are turning, to be removed.  You can't see them in the picture, but they are in there.  Then the side gears are removed along with the clutch packs.

The new clutch disks are soaked overnight in a friction reducing fluid.  Assembling them dry makes the unit chatter and its a long time until the differential oil works its way into the clutch packs. The rebuild kit comes with new clutch disks, metal plates and retaining clips.  Basically, the clutch disks spin while the metal plates are held stationary.  The clutch disks are splined to the outside of the side gears and the axles are splined to the inside of the side gears.  Hope I exsplined that well.

The clutch packs are assembled to the side gears and inserted into the carrier.  They then have to be compressed to gain enough clearance to get the spider gears back into the carrier too.  The tool to do this is just two large bolts with big washers and nuts.  Tighten them up and compress the clutch packs and washer.  When in place and the compression released, the spider gears hold tension on the clutch packs.  Getting the spider gears aligned so the center pin can be slid through them and the pressure released is somewhat difficult as the side gears need to be moved a bit. As they are under pressure, a bit of force is required.

[rusticretreater]

Now to reassemble the differential.  The first thing is to set up the pinion gear properly.  This is important in that done improperly you will get a lot of noise, wear gears funny and possibly blow up the entire unit.



 

There are two measurements that need to be set and those are pinion bearing preload and pinion depth.  The bearing preload is ensuring the inner and outer pinion bearings are squeezed together just the right amount to allow them to bear the brunt of the engine forces, have minimal freeplay and don't make noise.  The pinion depth is a measurement of how far the gear end sticks out into the housing.  This is required for proper meshing placement of the helical pinion and ring gears.

The problem is that one setting can affect the other.  Also the tools to set up a differential can be quite expensive.  So there are two methods to do this.  Trial and error and precise measurement.

In the trial and error method, the bearing is pressed off and a dummy bearing is used to reassemble for measurement purposes.  The bearing is reamed out a bit so that it slides on and off the pinion instead of being pressed on. The pinion is inserted into the differential and the yoke is bolted on.  Most yahoos in youtube videos use an impact gun and just tighten it down.  Spec is to torque it to 210 ft. lbs.  You then test its turning resistance which you want to be 13-19 inch pounds.  Most folks just settle on 15.



Torquing to 210 ft. lbs.  

 
Bad picture, but the arrow indicator reads 15 inch pounds.

This setting maintained by something called a crush sleeve.  It crushes as you tighten it, holding the clearance.  The problem is that if you happen to tighten it too much, you need another one.  In the trial and error method, this can happen too easily.  The solution is a crush sleeve eliminator kit which has a sleeve and a number of shims to allow you to set it precisely and remove the pinion to deal with adding removing/pinion depth shims without worrying about messing up the crush sleeve.

So this is all assembled, the carrier is inserted back into the pumpkin, bolts run down to 30ft lbs. and the side adjusters run down to 10ft lbs. to hold things in place.  A marking compound is painted on the ring gear teeth and the pinion gear rotated.  The tooth contact pattern is noted in the compound.  The contact should be in the middle of the tooth, both from top to bottom and front to rear.  Top to bottom contact is managed by ring gear backlash in a later step.  Front to rear depth is managed by shims under the bearing.  If it is not right, you disassemble everything again, adjust the shims under the bearing and reassemble, being sure to set the pinion bearing preload and side loads again.  Once you get it correct you disassemble it one more time, press the new bearing on, put it back together and hopefully you got it right.

There is a better way, but its a bit more expensive and it requires some math too.  I purchased the Yukon Pinion Depth Setting tool set which allows me to measure depth in thousands of an inch and set the depth to factory specs.



 





The pinion is installed as before with the preload set.  The ring gear and carrier is not required.

Differential height is the manufacturers spec from axle centerline to inner pinion bearing surface.
Pinion height is from the gear face to the surface where the shims and bearing rest. Measured by dial caliper.


 


The pinion was assembled using the .030 shim that was installed at the factory. So total shim thickness is .041 inches.  The rebuild kit contained pinion depth shims so a .041 shim pack was easy to construct.  Upon reassembly, I remeasured and found the depth off by .001, a thousandth of an inch which is close enough. Actually it is fantastic. Strange as it may sound, I was unable to find a stated spec for pinion depth.  The reason is that pinions vary in height, both factory and aftermarket. You just want to get the gear tooth pattern correct and depth close to 0 if you are measuring.

[Dan_Shade]

rusticretreater, 

That's a really good explanation.  I changed several gears in ford 8.8 rearends when I used to drag race.

Your post and pictures took me back. 

[Crusarius]

Sure is a fun memory lane trip for me to. I need to change the ring gear out on my front axle in my jeep. it seems to have the same issue my transmission did missing some teeth. Must be my 97 is getting old. its teeth are falling off

I dud just finish the ax-15 rebuild though so hopefully once I get the atlas in and new cross member made I can take it for a test drive.

[moodnacreek]

Last time I did this kind of work, on my '91 ford diesel, I went with a luk clutch kit with flywheel and love it.

[rusticretreater]

The next step is to reinstall the carrier in the pumpkin and set the ring gear backlash.  The backlash setting is important in determining the final location of tooth contact in a helical gear set.  Remember, the tooth contact pattern needs to be centered on the tooth both top to bottom and front to back.  Getting the pinion depth setting correctly set took care of the front to back part.

So the carrier is installed in the pumpkin and the retaining bracket bolts run down to 30 pounds.  The side adjusters are run down to 10ft lbs.  Movement is done by loosening the adjuster a bit on one side and tightening on the other side. Tightening from the drivers side pushes the teeth together and reduces backlash.

Once the carrier is in place and things tightened, a dial indicator is set up to measure the backlash and the ring gear carefully rocked back and forth to get a backlash reading.  The final adjustment should be somewhere between .003 and .005 inches.



 
Dial indicator reading .003" backlash.

After some finangling, I was finally able to get things where I wanted them.  The dial indicator is temporarily removed and the unit spun several times and then the backlash is remeasured.  The retaining bracket bolts are then torqued to 100 ft. lbs. and the side adjusters starting with the passenger side first are torqued to 75 ft lbs.  The unit is spun again and the back lash remeasured.  It should be between .005 and .008 inches.  If it is too loose, you can try to tighten the driver side adjuster a bit.  If it is too tight, the shop manual recommends loosening every thing up and trying again.  Luckily I had no issues.

The next step is to reinstall two retainer clips which when bolted on press on the adjusters and help hold them in place.  Then I used a slide hammer to remove the axle bearings and seals on both sides and then new bearings and seals were installed.  Finally the axles are reinstalled, pushing them in fully, putting the retaining clip on the end and then retracting them so the clips rest in the recesses in the side gears.  The center pin is then inserted.  Red threadlocker is applied to the holding bolt and it is installed.  Final steps are to bolt on the cover and fill it up with synthetic gear oil.

Driving the truck is quite satisfying.  Vibration is greatly reduced, power application is smooth as is the shifting of the trans and mileage is up .2 per gallon.  Since the howling of the differential is gone I can now hear all the other noises the truck is making.  Yikes!

Next up repairing the frame.

[rusticretreater]

I have finally dove in on repairing the frame on my truck.  And apparently its not a moment too soon.  The Dakota uses a two part frame to allow the use of different size cab configurations and bed sizes.  The spot where it is joined rusts badly.  The truck is a 2000 model, so it is in its 23rd year.  It is really quite amazing the truck was still functional given what I found upon disassembly.

The process requires removing the bed of the truck, removing the gas tank, exhaust, rear axle, shields, and then cutting through the rivets holding the frame sections together.  Cutting through the rivets allows the front leaf spring mounts to be removed.



 






Passenger side outside of frame




Driver side inside of frame




Driver side outside of frame




Passenger side inside of frame




This is a chunk of rust removed from the frame.  This is what happens to two layers of metal approx 3 millimeters thick each rust together.  The chunk is incredibly thick.







Frame pieces after rust removal.

Next I will be wet sandblasting the frame components and then starting in on the metal work to cut out the rusted metal and making plate metal pieces to restore the frame.  I know it looks bad, but it is not hopeless.

[Crusarius]

Looks better than the stuff I have been asked to fix.

[rusticretreater]

Thank you for the likes and comments.

Continuing on, I did a bunch of cutting, welding and grinding.  And then I did some cutting, welding and grinding, plus some welding and grinding and then I tossed in a bit more grinding.  Finally coming up with a repaired frame on both the front and rear halves.



Then came the next major hurdle. Over time as the frame rusted, it also gave way in strength.  The frame spread and twisted leaving everything misaligned. This also caused the truck bed posts to be misaligned(not vertical).



 



There were some convenient holes already available in the truck bed posts.  So I drilled a couple of holes in some steel box tubing I had and bolted them to the posts.  Then I got out Bertha, my power hydraulic piston set, set it up and used it to push the box tubing apart, straightening everything out as much as I could.

 



The rear frame was wet sand blasted and the exposed part of the front frame cleaned off and everything recoated with rust preventative paint.




And then I started back with the frame assembly.  You can see the hydraulic piston set on the floor between the box tubing.  While I had gotten the frame mostly straightened, it still needed a bit of pressure to get things aligned.  I enlarged the rivet holes and put in grade 8 fasteners.  And I also added a few extra.




And Voila`, with a wave of my hand, a repaired frame.



 

[rusticretreater]

Then for reassembly of everything else, I wet sandblasted everything and painted it all.  Axle and differential housing, brake backing plates, sway bar, leaf springs and shackles with rust prevention paint. The rear shackles and leaf spring bushings were replaced. I coated my not too old flowmaster exhaust in high-temp paint. One of the aluminum heat shields had corroded away around the bolt holes, so I pop riveted in some replacement metal(alum chimney flashing).  The heat shields were painted with the same high temp paint as the exhaust.  I tossed the old shocks and put in some KYB Monomax shocks with 3" lift.  And I redid the trailer wiring from the birds nest the previous owner had made two decades ago.  I even painted the gas tank with plastic paint.

Its a whole new truck now.




It flew through inspection and the guys at the shop wanted to know how I did it all.  Mighty proud I be.  8)  

[firefighter ontheside]

Wow.  That's a lot of work.  Great job.  Where's the final product pictures.

[moodnacreek]

Right there is the reason my next 1 ton will be a regular cab flat bed dump. Lifting the flat bed allows easy access to  the frame for cleaning and oiling. Likewise the cab corners, rockers, door posts, door bottoms and fender heels get oiled. Real running boards, not pipes or steps, along with wide and low mud flaps go a long ways in a salt state. My '71 f350 is this style and is solid all around [frame and cab] but the roof is rusting out from the inside, never dipped in the factory but I got over 50 years of use and it still has value. Not many will do the amount of work that dodge is getting.

[thecfarm]

A very fine job was done!!!

[Walnut Beast]

Definitely something to be proud of. A whole new truck as you say for a whole lot less than a new one. Since you have went this far if there is anything in question to do or on the wish list then do it! Nice job! 

[rusticretreater]

Its just a mangy old truck, with poor black plaint, peeling clear coat and dents.  Its an ugly duckling thats beautiful underneath.

I have a new pair of shocks for the front.  It needs a new front steering rack or some hoses. Probably both.  

[Peter Drouin]

When you have the tools and know-how your good to go. Nice job.