I tackled some planned projects on the car for better drivability and performance (electronic fan upgrade, grade 8 bolts through the the driver side motor mount and a torque strap on passenger side, and heavier guage starter and ground wires to help with starting). And after some cruising to make sure all was working, I started having fun and hurt something.

I need your help to figure out what I hurt on the rear or rule it out so I can focus on the trans. Gave it near full throttle from a stand still. Took off nice and straight and hard. Then felt like it was in neutral and gave me a really bad metallic clattering sound. I let off the gas and as the rpm dropped the car lurched and started moving fwd again but with the horrible metal grinding sound. I was literally minutes away from home so I limped home. If I hit the gas too much it freewheeled again and then would buck and catch with that metallic grinding as the rpm dropped. Oneven time it locked up and the car tried to stop in its tracks then bucked and moved fwd again. So I idled on home the rest of way. My drive way is steep and it didn't do anything weird when I had to give it the gas to go up. I also didn't hear or feel the grinding or anything else while idling forward but its kind of hard to over the Flowmasters.

So what do I look for.

I figured I'd start with the basics. Disconnect driveshaft and check trans mount, u joints. Lift rear of car put in N and spin the tire to see if they go the same way like it should. Then I'll put one side at a time on the ground and try spin the opposite tire to test if the SG is still holding and how strong. I'll look for any obvious signs of damage, listen for anything wierd.

Anything else I should look for before I start talking about opening it up? What to look for when I do?

What can I do to inspect the trans besides drop the pan and inspect the fluid? I just want to have some idea of what to look forward to replacing? Trans rebuild, wouldn't be happy about it but ok. Rear end, harder to find in good condition for my 1 yr only rear. Maybe use it as a chance to upgrade to Dana 60 or 727.

If I think of anything else I will add another post with the info.

It was the car in my signature, 71 Satellite sedan, magnum based 408, 904 with low gear set and trans go TF2 shift kit, 8.75 rear with 3.23 suregrip with 7290 u joints

I haven't gotten under it yet but will Monday. Right now I need to step away to keep my sanity and tomorrow is family time so no wrenching. I want to have a plan before I crawl under it. If you need any info off of it let me know where to look and I'll post it.

The good news is the wife told me "baby just order what you need to fix it". Gotta love the Mrs.

Sounds like you may have destroyed the flex plate between the engine and torque convertor.

great woman there my man!!!

That would be awesome but I'm not gonna get me hopes up. Will keep the fingers crossed though.

Thanks for the input. I didn't think to check it.

You think it could be the converter? I don't know what symptoms of anew injured one are.

does the Mrs. have a sister?

No, just a little brother

If you were spinning the tires in first gear, playing on & off with the throttle you may have hurt the sprag (overrunning clutch) in the rear of the trans. But with the loud metallic grinding sounds you described I still say you tore up the flex plate. Only takes a couple minutes to check it. Make sure you take a light under the car with you and look up into the bell housing area. The bolts could still be in the convertor with the plate torn up between the crank and the smaller convertor bolts.

Jack it up and drop the drive shaft then you can isolate the rear from the trans. I'm going with the rear end, trans will have to come out either way.

Yes, it could also be the rear end. He may have ripped up the ring & pinion since he did say it tried to lock up one time.

I'm betting on the rear axle. I suspect missing teeth on a ring gear (or spider gears if its an open differential) and the broken chunks floating around in the housing caused the near lock up.

The sad part is that if you broke the rear axle under power, you probably hurt the overrunning clutch as well, and it will fail the next time your pushing the car a bit hard.

Sounds like you have a good wife, do whatever you need to do so she stays around, good and understanding ones are rare to come by. Gene

That's what I'm thinking too, ring and pinion. No experiences to go off of just a feeling I guess. Im still hoping for the best though. I want to say there was a rotating scraping sound too. I happened so quickly though and I had so many thoughts flying through my head I probably missed some details.

I was already planning on sending the trans back to the builder to have the governor adjusted since I went to a steeper gear and stronger motor. If I drain the fluid and the inspection and checks show the rear to be OK I can have him go through the trans again. Everything I've read says exactly what you did about the overrunning clutch too so I'd have it checked out just to be safe.

Well, I disassembled my first 8.75 and feel pretty confident saying that its not the rear. I rotates through all the splines for about 15-20 minutes looking for any signs of damage and didnt find any. My SG may need to be replaced, or rebuilt (I think I have the clutch type) because I could turn one tire while the other was on the ground. Thats what that means right? I checked the ring and pinion and no signs of damage. while the rear was still together, after disconnecting the driveshaft, I turned the pinion and everything rotated nice and smooth, and quiet. There was no damage at the flexplate and all the u-joints were perfect as well. So Im going to try and lube the bearings with fresh grease and slap it back together.

I think its all in the trans. I was worried about both. This trans was rebuilt with a low gear set, Transgo TF2 shift kit and stock high stall converter. Is there anything in particular that I should do to is this time to ensure it lives? I've contemplated going SB 727 which means I would need to order a new yoke for the trans end of my new driveshaft but thats no issue really. I'll probably start a different thread just on trans build suggestions. I think I'll also look at some of the performance trans builders too, especially if the price will be similar. Last build on it was $1200.

Anywho, heres the pics.














What is this little piece. I cannot figure out where it came from. looks like a brake line clip maybe. I cant figure out where it came from and I hate not putting stuff back together the way it was.

That looks like the adjuster lock for the axle bearings

Yep. Axle end play adjuster behind the brakes on the passenger side axle.

At least you didn't grenade both the diff and the trans.

That's a cone type SG, and the fact you can turn one wheel while the other is on the ground means it's either shot OR you blew out the side gear axle splines inside the SG.

How do the axle splines themselves look?

http://www.moparts.org/Tech/Archive/axle/12.html

1st question: I didnt remove the axles completely so that I could reinstall them without risking damage to the axle seals in the event that I didnt find any damage. So... if I plan on lubing the bearings I need to pull them all of the way out anyway right? If so, then I'll pull them and post pics.

2nd question: If I were to order a SG unit such as Eaton True Trac is it something that I can set up on my own with basic tools or do I need expensive tools that I would only use once for this install in order to get things like the backlash set properly?

3rd question: If the setup is something that I wont be able to do at home because of the tools required, are there companies that I can send my assembly to to have a SG installed, and 3rd member setup properly and all sent back to me for a simple install? Or would you use a 4x4 shop to set it up for you? They have to do stuff like this all they time right? I dont have any Mopar specific rear diff folks near me that I know of right now.

Are you saying you think the the splines on the axles are probably damaged, or that the side gear in the SG are damaged?

Sorry for so many questions guys, Im trying to learn here.