Drivetrain Backlash.......

[Monkey Man]

I have a small amount of backlash in the rear of my truck that I have to track down, I'll look at the driveshaft, the diff and transfer yolks, the jackshaft and anything else you guys can suggest, I'd rather fix the problem now than do a full repair on it later........
Also, the rear diff has done a lot of work, the front is mint so I was thinking of swapping them, any reason I am unaware of that means I shouldn't?
Take Care

Regards - MM

[TOM R]

may be excessive backlash on the rear ring and pinion or worn ring gear, just a thought

[MSeriesRebuild]

If back lash is excessive, not likely it would be ring & pinion gears alone. It would certainly be doing some terrible howling at road speeds that would be unmistakable. More likely & very typical it would be the spider gear thrust washers that have worn out creating loose motion with the spider gear/side gear set up if it is indeed in the differential. A combination of several things in the drive line would be typical also. Usually when excessive loose motion is the deal without howling during acceleration, many worn areas are to blame creating a huge excess or back lash by the end of the line, the drive axles in the rear. This scenerio is perfect for breaking rear axle shafts, have you had that problem? No problem with switching the front diff to the rear, but if it's been worked hard, it isn't likely that will solve the whole problem. Unless you spot the obvious during a drive shaft inspection, etc., getting ready to dig deeper is in order.

[Monkey Man]

Charles......
I have been looking at it for a little while, I'll be intending to do the diff swap next time I have the truck off the gound but that'll be a few months yet. I have broken axles before but this was before the backlash was noticable, I think it was more caused by my lack of patience on the throttle and the clutch plus the fact my truck was a tow truck in it's previous ownership and had a bevvy of casual drivers to keep it well and truly stressed. The backlash isn't too bad but there is sometimes a distinct "slip" in the rear when applying power, I suspected the yoke slipping on the shaft or even the spider gears "heeling over" a little as the torque is applied, either way it is the top of the top 10 GOT TO DO list as getting another full diff here is unlikely. Brigand sent me a secondhand crown and pinion some time back, it is a good backup if needed and I noticed AB has the spider kits fairly cheap too sso I most likely won't get stuck but prevention is the best cure, I'll have to schedule some "dirty time" with my truck
Take Care

Regards - MM

[nivek]

Picked two sets up for less than 50 usd for both. Shipping was spendy "just across" US.

The kits are complete with everything but the Ring and Pinion themselves.

If you find you need some of the small parts, I have an entire kit here extra.
(Ended up not having to do much to one of my difs, other was a wreck waiting to grenade)

Spider gears, brass parts, shims and some parts I hadn't even uncosmolined yet.

They'll be here on shelf, not going to toss them in a fit of cleaning shop madness..

kevinL