Help diagnosing what appears to be a bad/seized differential

[Ultramaroon]

I'll guess a busted pinion tooth


edit: wait, no. nothing in the fluid. ....hmmm

[NoHaveMSG]

Originally Posted by Ultramaroon

I'll guess a busted pinion tooth


edit: wait, no. nothing in the fluid. ....hmmm

I was thinking the same at first.

Wonder how much play is on the input yoke. Pinion crush sleeve causing excessive backlash?

[paintdude258]

Originally Posted by norcalpb

How do the bushings on your driveshaft look? When I had mine replaced with the metal torque solution ones (a mistake), the stock rubber ones were super deformed. Not sure that could cause a noise though.

When I had the driveshaft off and replaced it with another, it was a bit squishy, but didn’t seem deformed or broken!

[paintdude258]

Originally Posted by Ultramaroon

I'll guess a busted pinion tooth


edit: wait, no. nothing in the fluid. ....hmmm

I did look close at the fluid, maybe I saw a light bit of shimmer, but nothing like a tooth floating around.

[paintdude258]

Originally Posted by NoHaveMSG

I was thinking the same at first.

Wonder how much play is on the input yoke. Pinion crush sleeve causing excessive backlash?

Input yolk meaning the part of the diff that the driveshaft connects to? Therea definitely play between left and right turns before anything engages. No shortage of it

[norcalpb]

I know you mentioned you drained the diff, but have you drained the transmission yet?

[NoHaveMSG]

Originally Posted by paintdude258

Input yolk meaning the part of the diff that the driveshaft connects to? Therea definitely play between left and right turns before anything engages. No shortage of it

Yes. Pinion flange, input flange. Yoke was not the right term. There is a crush sleeve on there, wonder if it is causing you to lose preload. If you grab it does it shift in and out a lot? It should have some play. I am really taking a stab in the dark here. It doesn't look like anything upstream to me. It seems to be diff related.

[paintdude258]

Originally Posted by norcalpb

I know you mentioned you drained the diff, but have you drained the transmission yet?

I did, all was good!

[Grady]

Originally Posted by paintdude258

I have lifted the rear of the car up, taken the drift shaft off, and found that the car ran fine. Problem starts when the drive shaft is bolted to the diff.

I have replaced both rear axles, so confident they are not the culprit.

Differential looking more and more likely.

Take diff apart and post pictures.

[DarkPira7e]

Originally Posted by Grady

Take diff apart and post pictures.

Hopefully not their first time smelling burnt ass diff fluid.

[Flarpswitch]

Originally Posted by paintdude258

I have had to replace the front and back right side coils several times from hitting curbs and pot holes. The roads are terrible in my area, and i diddd have to learn how to drift some how many many moons ago. I suspect this level of abuse has taken it's toll on the diff! Good call pointing out the beating that I have put the car through in it's years. I don't drive the car easy, as it's most fun when it's right on the tail edge of control.

Not all of the insults that you throw at the drive line come back to bite you right away. Taking a turn around the corner, a pedestrian walked out in front in the dark and I hopped a curb to avoid hitting him. The trailing arm on my Triumph Spitfire broke from the impact. Driving slowly a few blocks to home I easily replaced the broken part from my treasure trove; we had well supplied salvage yards back then. All was well after that, so I thought. A month later, I was leaving a friends house at 2AM and it must have been about 20 degrees F out. I stopped for a light and when it changed, I let out the clutch and bang. The next day I discovered that the right side inner drive shaft snapped right at where the splined end fits into the sun wheel gear. This sort of stuff only happens when you are far from home during the worst possible weather conditions.

[terboboost]

I don't think you're going to get a good answer from this forum, they are just guesses, even if by experienced people.

You need to work on isolating the issue. Take the wheels off, does it still do it? Remove the CVs completely, does it still do it? Remove the brake calipers, does it still do it? Or just open the diff and inspect.

When I watch that video, it seems to me the hopping STARTS from the driver side wheel. But these videos can be so misleading because everything is connected.