Just picked up a deuce, some issues!

[YkDave]

Well for f'k sakes...

I have resolved one issue and come up with another

Tore everything out of the reduction on my parts truck. Aside from some nasty buildups of crap in some areas i would be tempted to say that it was nearly new, everything appeared to be in great shape. So i threw the whole thing into the truck, and crossed my fingers and fired it up...

WOOHOOO low range works!

Try high range, clunk... jammed up solid. tranny wont move at all, something is binding in the reduction unit when trying to use high range.

So i guess, it looks like its all going to be coming out again!

 

[Gunfreak25]

Many of us here feel your pain as well! Glad to see that you almost have it fixed, a lot of other people would have given up by now and just scrapped the thing or parted it out for cash. Your either really hard headed or a glutton for punishment like me. Actually, anyone who collects/maintains/loves these old GMC's is probably a real glutton for punishment. It's no fun driving something like a Prius that you never get to toy around with in the garage!

Keep us updated, I can't wait to hear when you've got it running like it should!

 

[YkDave]

LOL

Well, if you havent figured it out yet, i dont mind being behind a set of wrenches.

But, yes, problems like this do make me want to tow it out of the shop and burn it!

But, on the bright side, the only thing the truck has cost me has been a couple pails of oil and a filter. Thank god for that parts truck!

I will sit down with the old reduction unit tomorrow and rack my mind as to how it could be binding up in high range, then go from there. luckily its actually not too bad of a job to R+R the reduction unit

 

[Stan Leschert]

High Range reverse is completely useless, as you just found out by the fractured parts. If you want to go in the behind direction ONLY use low range! Anything else will bugger the tranny. Yes, this truck does untilze the sprague , so make very sure that the tranny is set for the direction in which you wish to go. Letting the truck coast in the wrong direction of what you have specified with the shifter will cause your wallet to empty in an extremely rapid fashion!

Make sure to down load the manuals from the resource section of this site. If you require hard copies, which you don't mind getting grease on (much cheaper to replace than laptop), just do a search on E-Pay. I paid $25.xx plus duties per copy.

If you want the Cloverdale Paint code for OD, I'll run out to the truck and copy the numbers off of the rattlecan touch up bomb!

Good luck, and keep posting pics!

 

[sirmrtow]

welcome to the site and good luck

 

[YkDave]

from what i have read, the only issues regarding high range reverse have been directly related to low line pressure. My line pressure is perfect, thus i expect no issues by using it.

The original issue was from the direct clutch return spring breaking into a million pieces. IMO this could not be related at all to reversing in high range as the direct clutch is engaged any time you are in high range, going forwards or reverse. From my reading, the issure regarding reverse/high range is burning out the reverse clutches due to low line pressure (using high range puts much more load on the clutch and coupled with low line pressure/less holding power = slipping)

 

[YkDave]

ive just been rattling my brain for the past few minutes trying to figure out why this thing locks up when trying to use high range.

The only thing i can see causing it to do this would be if the driven cone were to get suck to the case and the clutch pack were to remain engaged...

Or maybe the control valve is f'd (i used everything from the parts truck) and its trying to apply the clutch and the cone at the same time which of course would lock it up. I will be doing a pressure check right now to see if their is pressure on both the clutch and the cone at the same time.

Ive just discovered the built-in park brake for these things LOL

 

[Gunfreak25]

I doubt this would cause the lock up issue you are experiencing, but what kind of fluid are you running it?

 

[YkDave]

clutch and piston pressures are acting normal. time to dig into it again i guess and see whats going on. something has to be binding up in the piston/cone which is causing the whole thing to bind up when the clutch is engaged.

 

[YkDave]

well, that was exactly it!

The piston was stuck to the driven cone. i guess i should have pulled the whole thing apart after pullitng it off the other truck, but i was in too much of a rush to get the job done because i needed the truck out of the shop!

Luckily, i didnt have to tear everything apart again. i was able to just take out the ujoints, slide the reduction housing back a few inches, then use air to move the piston out enough that i could get between it and the driven cone with some small prybars. released the air so the clutch springs could put some load on it, then a couple of light taps with the little brass hammer and it popped apart

 

[Gunfreak25]

Great! Any chance you could get some video of the truck driving?

 

[YkDave]

i would if i had something to take some video

But will likely have some pics soon. Me and a buddy are taking the deuces out for a test run when he gets back into town. we are both curious to see what they are capable/incapable of doing!