Welded rear axle

[converted_to_datsun]

So I suspect the previous owner welded the axle... How can I know for sure? I floored it in the dirt the other day and clearly make trenches with both rears. And if it's welded what are the pro's and cons? Does it affect fuel economy or just handling?

[datzenmike]

Even open diffs can sometimes seem to spin both wheels.

 

Lift one rear wheel and place transmission in neutral. If you can't turn the raised wheel it's been welded. I suppose it's remotely possible you have an LSD.

 

Can't see it affecting economy but it's hard on the axle splines and chews up the tire rubber faster. Good for going straight but causes severe understeer when cornering. Once the rear end comes loose on wet or snowy roads it's extremely hard to recover control.

[converted_to_datsun]

I'll try that and see if it turns. It seems to break free in low speed tight corners too. At speed it seems fine tho.

[ohmrchristopher]

Drive in a parking lot.

 

Eg, tight circles, my diff is welded (not my choice either) and the tires will skid and chirp.

[moparvwfreak]

i have a welded diff for my 620, the ONLY reason i would use it is if i was drifting or wheelin. also had a welded diff in my 84 4Runner. loved the truck, hated the diff. turning was not fun. especially with 33s and a welded diff. if it is welded, search out another diff.

[converted_to_datsun]

Well it's not welded. But it does seem to have an issue with something in the tranny or something. In 3rd or 4th if I let it lug at low rpm is makes a kind of clunking or knocking till I give it mOre gas or put the clutch in. Doesn't seem to affect anything with the way it drives. Any ideas? Clutch? U joint? Rear end...?

[DAT510]

Might be U joints, think of there being slack in the joints, then when you engine brake or just let it coast with the clutch engaged, the wheels want to go faster than the engine then when you disengage the clutch the wheels can go as fast as they want.

Well that's how i think of it

lift the rear end and put the truck into gear, try turning the shaft. you'll find out if it's the u joints

[datzenmike]

Sounds like the drive line clunking between acceleration and deceleration. There is some gear lash in the transmission and diff. A worn U joint can aggravate this too. It's more noticeable in higher gears and the motor lugging at low RPMs and heavy throttle..

[converted_to_datsun]

Oh sounds about right. I think I can hear play in the u joints when I turn the shaft. I am putting a 5 speed in in a couple months... Would that fix it? It sounds like it could be in the tranny but it's really hard to tell because I have allot of exhaust noise drowning it out