look under the tilting seat - find plate/decal with tractor's full model # - go to MTD website to search for manuals - follow manual instructions for adjusting clutch/brake mechanism. may also need to replace existing ground drive belt if stretched - replace with OEM belt for best operation.

Note: Automotive belts, or hardware store belts, are not suitable for lawn tractor use! You are wasting yer money by buying them! Take the advice of the other guy who posted the advice! We folks have been repairing lawn tractors and related machinery for many moons, and we offer the advice free and clear. I know, if you go to a real dealer of MTD machinery--they will tell you the same thing!
I know of one guy who made 4 trips of 15 miles one way, to a hardware store, trying to find the right size of belt! And ended up buying the correct belt that was designed for his machine! Bought it from the Dealer!

I am using a fully jacketed, OEM equivalent belt made by Stens.

Fish, thanks very nuch. that was exactly the problem. the bolt was there but the nut was not. Now it works fine, though the "clutch" seems to grab too high but I can live with that.
Thanks again.

Tom

I have a 1988 MTD 38" 12 HP, 7speed.
The Clutch engages very high, almost at full pedal release,and
gives a real lurch forward as it engages. Is there a way to adjust this? It has a new belt, fully jacketed, proper type.
The belt from the engine to the intermediate pulley is the original but appears in good shape.
Thanks in advance.
Tom

Fisher,... I cannot Thank You enough for your simple, but critical tip on this frustrating situation.

I had days into diagnosis the belt jumping off in reverse also I had drained the fluids twice from my mower to flip it over to inspect the problem. I was going bananas trying to find this problem. I had realigned the idler pulley countless times. And even had a brand new OE belt that left me frustrated.

I had replaced the gear set inside my transaxle last season and this is when this new problem of spitting the belt off in reverse started. It did not make sense as we all know the direction change takes place inside the transaxle house, not a reversal of the belt.

I had read your post and glazed over it. I just happens to double check the mounting bolts for shtz and giggles and noticed a rusty point on the frame at the front of the transaxle. And there you have it, I did not replace that dang single bolt and it would allow the transaxle to torque up when engaging reverse thus, misaligning the belt.

I was at my wits end. My mower runs like a raped ape now. I never would have guessed. Thanks again for taking the time to post that info up.

Unfortunately Fish is no longer an Active Member , he swam into the Arboriste Site 5 or so yrs ago ! Cudo,s Fish !