4 weeks ago my car broke down and while pushing it the rear tire ran over my foot. I have a thread 4 weeks ago on that. Still on crutches.

The car lost power and went into a neutral mode. Now investigating I have it on jacks and tested it with engine running. The wheels all spin in each different gear and the clutch engages and disengages fine. But when I put the car down and put load on it, it goes back to total neutral mode where it won't move in any gear.

So my first thought was tranny since I knew the clutch is OK. But I just had the differential rebuilt and I put it in a few weeks ago. Usually if a new problem shows up its almost always what ever was just toyed with.

So I disconnected the drive shaft from the tranny since I was going ahead with tranny removal. But I noticed when I spun the driver side tire to rotate the drive shaft, the other wheel didn't move at all. I think from the millions of times I've removed the tranny both wheels move at the same time but I'm not positive. So right away now I'm thinking the diff somehow was not done right and is broken.

When I go to the rear passenger tire and rotate by hand, it does not move the driveshaft or other tire.

So I need a sanity check first. Should both tires move together when turning the driveshaf? THX

 

Sounds like something wrong with your differential. It's a positraction unit, both wheels should turn together.

 

With the car on the ground, upon releasing the clutch, does it make any noise?
A bad rear end would most likley make noise if there were some damaged parts.
I think your clutch is slipping alot. Might be enough friction to rotate the wheels with no load in the air but not enough to push a 2 ton load. Maybe you got some oil on it somehow. Maybe from a oil leak.(Rear main)? Just guessing

 

It's a brand new clutch and it's not slipping. I already tested that possibility.

If no posi additive was ever used, would that make the posi not work?

 

If you can rotate one tire and get no movement from the other side it sounds like something busted in the diff. As said above a posi wil rotate the other wheel the same direction. Even an open rear will rotate the other side, but it will be in the opposite direction. If no movement I would suspect the spider gears or something internal is broken. Time to remove the rear pumpkin.

 

You've got something broke in there, you should never be able to spin one wheel without either the other wheel or the driveshaft spinning.

 

it is simple, put it in your 'neutral mode' where the problem is being reproduced.
if the drive shaft is spinning and the wheels are not, then you have a rear end problem.
if the drive shaft is not spinning then it is a tranny or clutch problem.

 

IN FACT it is almost impossible to get the symptoms you describe, UNLESS you have not installed the spider gears.....you better go back and look around man......wonder if the cross shaft was installed, and the spiders just spun out because it's missing??I would think they'd jamb up in the bottom there but maybe you got crazy lucky....

 

That says it all. Serious diff problems.

 

Thanks for the confirmation. That's what I was thinking. I just paid $1700 for that rebuild. I'm so pissed you have no idea.

So I just confirmed also by torquing the driveshaft disconnected from the tranny and held the wheel that could spin in place, and sure enough the diff slipped and I could turn the driveshaft with no tire movement. So out comes the diff for the second time.

With my injuries and time and money I'm thinking lawsuit if they don't fix it for me. I did this at J&D Corvettes who have been good to me over the years so we'll see what happens.

 

J&D has always had a good reputation. I am sure if they made a mistake they will rectify it.

I know you are frustrated but keep your cool and be professional when dealing with any vendor. At the end of the day you will get more with honey than XXXXXX.

 

Did it run over your ankle too or just your foot? Was your foot flat or did it get you sideways?

You are correct, with limited slip the other wheel should spin in the opposite direction. With an open diff, only one wheel spins and the DS count is twice as high.

 

Over my ankle forcing me to the ground and torquing my knee. MCL stage 3 damage. 6 weeks to heel plus rehab. Ankle is healing OK. I'm on week 5. No surfing for a while.

Got diff out in around 4 hours. Took to J&D and got no hassle. Looking at diff when out I could move the yoke that didnt move out about 1.5 inches. Obviously snap ring is off but what else? We'll find out soon.

 

No, with limited slip and tranny in neutral both wheels spin the same direction. With an open diff both wheels will usually spin the same direction also, but it is easy to hold the other wheel and the driveshaft starts going 2x speed.

 

Well J&D just called and said I sheared a yoke in two. I asked how that could happen since they gave me two new yokes with the rebuild. He implied I must have floored my car and I'm not suppose to do that.

He also said the yokes were NOT the hardened type so he is going to give me 2 new hardened yokes now.

The thing is, when the car broke I was pulling out and up hill from a parking lot and did accelerate hard. But brand new yokes should be able to tolerate the acceleration I did since it wasn't WOT at the drag strip.

So I think there must be some kind of material flaw with these basic yokes he sold me. Hopefully the hardened ones will last. So beware and always get the good ones. No charge to me he says so all is good.

 

Sounds like some cheapo yokes were used. I have hammered the crap out of my original yokes on many occasions and even drag raced with them and they did not break. I broke a rear end but not the yokes.

Your not supposed to floor it???? Who are they kidding.

Nice to hear they are fixing it for no charge though.

 

All yokes are hardened. If they weren't the tips (inner end) would wear out in no time.

They probably put some cheap imports in it. Tons of that stuff floating around. I wasted $600 on crappy diff parts some years ago from a supposedly reputable vendor. After less than 20K miles I found one yoke as well as one spindle had twisted and was ready to snap. The yoke ends had also worn down 0.050". Bad metal and/or hardening.

 

no surfing?Well I guess you can't in that weather anyway.good luck.maybe surf down your street?lol

 

Post a pic of the failed yoke if you can. An extreme case of poor quality metal will be easy to see.

 

Sorry no pic of yoke but he did show it to me today. About 1.5 inches from the end was where it sheared off. I'm actually a stress engineer and do this kind of stuff for a living so I knew what to look for. It showed typical signs of overload and not fatigue which you would expect from brand new material.

I'm positive it was China cheap *** crap. He tried to also say my wheel alignment had something to do with it and showed me the good yoke on the end had something rubbing against it. Not sure how the camber rod adjustment could actually affect the non adjustable yokes.

Again I've always liked J&D and think they're great. They've always treated me well. I just hope whatever new yokes they stuck in actually ARE hardened or heavy duty heat treat material.

My original yokes never broke other than the ends wearing down so makes you wonder. I did many WOT with those.