450 slipping clutch

[gvette85]

Just bought a 1970 straight 450 dozer from my father in law.Pulls great when cold but after running for a while clutch slips badly,even to the point it won't move.Once it cools it's good to go again.Any ideas for an easy fix or do I need to plan on a clutch replacement?

[jtrichard]

check the adjustment (free pedal)

[Tigerhaze]

It will be great if simply a pedal adjustment, so you should go ahead and try that. "slipping" can happen at two locations- a malfunctioning HLR transmission that is not getting power behind or slipping steering clutches on each side of the machine that transmit power from the HLR to each final drive.

Unfortunately when they slip after heating up usually means that oil is soaked within the fiber discs of the steering clutches and comes to the surface as they warm or that the HLR has a serious issue.

Because you are not experiencing slippage differently along each side of the machine it could be an HLR issue- they are known for having major slipping issues when warm. Let's hope that is not the case for you.

[jtrichard]

Tiger I believe 450 has a main engine clutch (pedal operated unlike our 2010s) His problem could still be in HLR . Main clutch OR steering clutches Less likely to be steering as it would have to be both sides to just stop pulling .....HOPE it is lack of free play (fingers riding throw-out bearing) and "just needs adjustment" but we know what that usually means

[lti]

Just put in a new engine clutch it would not move with the HLR. There is a valve that works with the clutch pedal its inside the clutch housing it is adjustable from a hole off to the side of the air cleaner canister on the top side of the clutch housing.It regulates how much oil from transmission goes to oil cooler. On ours they had to much going to cooler trying to make it work as clutch. Make sure you have the right amount of free play on clutch pedal and then can adjust that valve and this one is moving now.If you have any questions let me know.

[gvette85]

Thanks for the info guys.I'll check the free play first,however I know it has some free play so I don't think that's it.Both steering clutches seem to work fine up to the point it starts slipping.A mechanic friend of my father in law mentioned the valve you speak of but he's leaning toward an oil soaked engine clutch as the culprit.Looks like I'm going to get greasy.Thanks,again.

[lti]

If you go into the clutch housing if there isnt a drain hole in the bottom make one. This machine there wasnt one that we could find, clutch was rusted right to the fly wheel, throw bearing stuck in the on postion, had to cut it off.. A pool of water maybe, some oil in the bottom, couple of quarts or so power washed it out no drain there is now with the help of a torch about the size of a quater. Also make sure your pilot bearing is first then the snap ring then the clutch disc who ever put this one together had snap ring pilot clutch disc will not mate and will lock engine took that engine in and out 3 times before we figured out the right lineup. The service manual doesnt tell you very much about the lineup.

[gvette85]

Thanks for the tip.Just spoke to my father in law and he told me he had already drilled a 3/8" hole and drained water out.

[lti]

Also when in there, this one had a bracket on each side of housing to the side frames 2 bolts on each bracket. One side comletely gone bolts were broke in housing no way to get out so local welder welded an iron plate from frame to housing its in there now. Other side seemed to look all right didnt try and work on the bolts looked tight left them alone.