Rear end thumping still

[blackthunder50]

Well, I had the U joints replaced tonight and drove the car back home and noticed that from the rear end, it almost hums at 40 mph when in N. Then when you come to a stop it thumps and stops when the car stops. I noticed alot of greasy oil around the front of the rear end, almost sprayed all over the bottom of the car and all over the torque arm. I think the pinion seal is leaking bad, I just hope that the rear wasnt damgaged from low oil.

Also, after the U joints were replaced, now the car has awful vibrations at cruising speeds, the steering wheel shakes bad and never did before.

In addition the guy that works on the car wants to take off the headers to make the plugs and wire install easy. Hes a Gm technician and works with my grand father so he knows chevys. If he does this do you think i should just pick up some chrome bbk shorties and have them put on instead of the crap stock manifolds???

[Trash man]

id be more concern bout your rear. get the fix, then get some upgraded wires, plugs and then if money allowes, get some nice flowing headers. but thats just my couple pennies

[TraceZ]

While changing plugs and wires on a LT1 is no picnic, I'd be really leary of anyone who says it would be easier to remove the exhaust manifolds to do it. That is really doing it the hard way.

[4THGEN Z]

was the driveshaft marked before it was removed? If not, it could be out 180 degrees at the differential pinion yoke.

[blackthunder50]

It might have not been marked, the car is going back into tonight to get checked out, he was under a time limit for closing hours because he does work on my car after the shop hours at the dealer. He's going to fix the problem, like you said it may have not been marked, I'll find out tonight. As far as the plugs and wires he said he can do them no problem by taking the exhaust manifolds off, which I was a little suprisd about because i have read you guys doing them yourselves. But I figured with those off I could probably throw on a set of BBK shorty headers which i can get really cheap.

I'll post what happens tonight with the rear end problem when its done (hopefuly) Thanks guys

[TraceZ]

It might have not been marked, the car is going back into tonight to get checked out, he was under a time limit for closing hours because he does work on my car after the shop hours at the dealer. He's going to fix the problem, like you said it may have not been marked, I'll find out tonight. As far as the plugs and wires he said he can do them no problem by taking the exhaust manifolds off, which I was a little suprisd about because i have read you guys doing them yourselves. But I figured with those off I could probably throw on a set of BBK shorty headers which i can get really cheap.

I'll post what happens tonight with the rear end problem when its done (hopefuly) Thanks guys

I think it would be easier to just pull the engine to do the spark plugs. As long as the engine is out, you can replace it with a supercharged stroker.

Seriously, though... just getting the passenger side manifold off is going to be 2 x harder than changing all 8 spark plugs normally. That really bothers me that a supposedly experienced mechanic wouldnt know better.
However...
If the goal of your project is to install headers, during that install would be a good time to replace the plugs and wires. But believe me, that will be *way more* work than just replacing the plugs and wires the normal way.

[blackthunder50]

Yea it definetly confused me, but he said the wires are routed behind the manifolds, i dunno though Im going to talk to him today when I drop the car of cause I will most likely be in there helping him out the whole time. Usually all you would have to replace to make it easy is the starter, alternator and steering arm thing right? Im going to search around for hints/advice for the install.

One thing, I got MSD 8.5 mm wires, do they need to be put back in the plastic wire looms that encase the factory ones or do you just install the wires?

[TraceZ]

Yea it definetly confused me, but he said the wires are routed behind the manifolds, i dunno though Im going to talk to him today when I drop the car of cause I will most likely be in there helping him out the whole time. Usually all you would have to replace to make it easy is the starter, alternator and steering arm thing right? Im going to search around for hints/advice for the install.

One thing, I got MSD 8.5 mm wires, do they need to be put back in the plastic wire looms that encase the factory ones or do you just install the wires?

I recently instaled Taylor Spiro-Pro wires in mine, although they were 8mm they did route snugly in the factory locations. I did most of the installation from underneith the car. I also used black plastic wire conduit to cover them for added protection from dirt, arcing and abrasion. I would do my best to get the 8.5 wires to go in the factory clips, but it might too tight for some of them.

Does MSD make a 8.0 mm wire? if they do I would get those and make sure it is routed in the factory clips. I've heard bad things about the Taylor wires since I bought mine. I havent had any problems, though. I should probably replace them with the MSDs anyhow, just to be safe.

[4THGEN Z]

IIRC the 8.5's will not fit in the looms, especially the ones behind the P/S pump. 1 thing I did was route the pass side wires behind the tensioner through a passage which bypasses that PIA route going behind the P/S pump and gets you up the pass side of the block directly.

[blackthunder50]

Just got back from the shop and figured out everything thats going on. We replaced the torque arm bushing cause the other one was torn. The rear end had no oil in it, completely dry ! The seals are bad and the bearings should be replaced, the gears have a few decent chips in them. As for the rear, Im just going to go with 3:73 gears new seals and bearings. This will take care of that thump that is barely noticable after adding more oil. We rotated the driveshaft a bit and that fixed the vibrations along with the torque arm busing fix.

On the other hand, were just going to rip those old manifolds off and do spark plugs that way and throw on a set of bbk ceramic shorty headers. The mechanic said he'll have no problems doing them, compared to some of the stuff he does at the shop this is nothing for him! Hopefully its all going in starting saturday morning. The lift is amazing, i wish I had it in my garage! Hopefully this takes care of all my worries of the rear going and getting those plugs changed.