drive belt on LT70

[Beavertooth]

I have a 62cat diesel on my LT70. Belt tension set at 9lbs with 3/8" deflection is WM recommended tension. The guys in Indy tell me not to go over this. Tim at WM in Mississippi tells me I can't go my tension guage to just gradually tighten it up until it quits slipping. This is how I have been running it for the last 1000 hrs. If I run it at 9lbs I can't saw anything and push it hard at all. I run it at 13lbs. WM recommends 14lbs on new belt and 9 after so many hrs. I put new belt on 1000hrs ago set at 14 and had no problem until it stretched down to the 9lbs then I had to tighten it back up.  Just wondering what everybody else is running.

[customsawyer]

I can't tell you what tension I run as I go by feel. Like you used to on a alternator belt in the older trucks. Just don't go to tight on those Cat engines the front main seal don't like it.

[ladylake]

 Does it have the 3 groove 1 piece belt like my B20, with the old 27hp Kohler no slippage at all running it rather loose and with the 29hp Isuzu   diesel  I have to run it way tighter than I like.  I had the pulley off last week to replace the rear seal and it was shiny on the outer edge meaning the belt was hitting the outside before the grooves. To me I don't think the 3 groove single belt works good or maybe the belt or pulley is wore too much.   I'd guess 3 single belts would get down in the pulley better and not slip but would not stay on as good.   Steve

[MartyParsons]

 Rev. A7.07+: Measure the belt tension with a gauge. Proper tension for
a new belt is 3/8" deflection using 14 lbs. of deflection force. Use 9 lbs. of deflection force for subsequent adjustments.

NOTE: A retrofit is available for the belt tensioning system
(Part No. 038934). Modified pivot brackets increase the
range of motion to reduce strain on gearbox. If the system
has been retrofitted, the grooves in the belt tensioner link
arm will no longer be used to indicate proper belt tension.
Use the specifications above to check belt tension.

Hello,
I checked the manual as we should always do.  :P If you chose to go tighter on the drive belt then you may damage the crank shaft on the Cat Perkins engine. It may turn out to be a major cost.
The three grove molded belt will last longer and pull evenly than three belts. At one time there were matched sets available from belt manufactures. The belt WM has 3/5 v 950 is Kevlar reinforced.
The grooves on the belt tensioner link should not be used on any LT70.
Hope this helps,
Marty
The part # for the belt tension tool is 016309. Less then $ 20.00 and is an accurate way to check any belt tension when used as directed.

[barbender]

 I just got a new drive belt and the tension gauge for my LT 40 with the 40 horse Lombardini, 7/16" @ 15 pounds for this engine. My old belt looked fine, but it wore to the point that it was getting down in the grooves, I had it way over tensioned (figured that out when the guage arrived ), and it was still slipping. New belt installed and properly tensioned, no more slippage  ;)