Driveline clanking

[Inspector]

Can someone tell me if a gt-5 rear diff is a limited slip? Here is what I got. My old 93 is making a terrible clanking sound when you put the power to it from a stop. If you ease into it its ok. It was making this sound before we changed the clutch and pressure plate out and is still making the sound after all that work. The clutch was bad and needed to be replaced. We replaced the flywheel as well. I am thinking that the rear end if it is limited slip, is the culprit. How do I identify it as a limited slip? The RPO code only says that it is a GT5 which is 4:10s. I'm hoping that it is the rear end that is making the driveline clank and buck like a spline is slipping. Help.
Denny

[Hubert]

A "clank" or "TINK" sound might be the driveshaft resonating from worn out ujoints. Depending on how many miles though the driveline develops some slop that does the same thing.

You can jack one wheel up and try to ease off the jack if it moves limited slip; if you just spin a wheel its not or worn out.

[JohnC]

The locking differential is a separate option, G80.

[Inspector]

This is more like a slip. It just bangs the whole driveline. We installed new U joints in the process of the clutch change. I fear that the output shaft of the NV4500 is slipping within the input shaft of the transfer case eg the splines are worn out. How this could happen I don't know. If that is the case all has to come out again and a trans overhaul is in order. I was hoping that it would be the rearend. As I remember, on the RPO code list in my 03 it list the GT5. It is a locking diff in that truck. I am going to look again but I think that it is also a GT5.
Denny

[Inspector]

John C. or Ronniejoe:
I started this thread in the wrong place. Could you move it down to the 2500/3500 drivline area please.
BTW this truck is a 3500 deully EC.
Thanks
Denny

[JohnC]

GT5 tells you what the gear ratio is. G80, if present, tells you it is a locker. If it doesn't say "G80" then it rolled off the assembly line with an open differential.

Moving to the drivetrain forum.

[rjschoolcraft]

Even if this is not a limited slip, it could still be in the rear end. If either the final drive pinion and ring or the differential pinion and side gears have one or more teeth missing, the "clank" you describe will occur. I would suggest pulling the cover off the diff for a peak...

I really doubt that it is a spline problem in the manner you describe. Very, very rarely will something like that occur. Usually, if you wear out a spline, it will break all the teeth in a very short time and slip completely. Splines cannot "jump a tooth" because all are fully engaged all the time.

[DA BIG ONE]

Some t-cases like New Process w/active on demand have a clutch pack (10 clutch plates/9 steels) w/heavy spring between the tranny and t-case output to absorb drivetrain shock when the clutches wear, or the spring gets weak it will clunk like hell!

[DmaxMaverick]

Try greasing the output spline. Many of them have the "spring wind-up" issue, and yours may just be an extreme case. If this happens taking off after a stop, it would be the first place I'd look.

[royalglen]

An easy way to tell if a non-slip is noisy is to find a quiet parking lot and make tight turns-if differential snaps or bangs thats your noise.A can of non-slip additive may cure it. Good luck.

[Inspector]

Thanks everybody for the come backs. Keep them coming. We are going to pull the rear drive line out tomorrow and go for a drive in 4HI to see if we still have the problem. If we donot then we know where to go. But if any of you have had this problem post em up.
Thanks
Denny

[DmaxMaverick]

Originally posted by Inspector:
Thanks everybody for the come backs. Keep them coming. We are going to pull the rear drive line out tomorrow and go for a drive in 4HI to see if we still have the problem. If we donot then we know where to go. But if any of you have had this problem post em up.
Thanks
Denny I wouldn't suggest driving with the rear driveline removed. The fluid in the transfer case will spill out. The tail seals around the driveline yoke. Pull it, and nothing keeps the fluid in but gravity. You could use a service plug, but they aren't designed to be used on a vehicle being driven. The output spline may shread it.

[Inspector]

We did go for a drive with the rear driveline out of the truck. Oh forgot to explain that I have a Gear Vendors installed with a fixed yoke.
I still get the racket from the transmission or transfer case. This proceedure efectively ruled out the rear diff and the Gear Vendor as the problem.
The T case is a 4401 so I don't believe that it has a clutch pack in it. The 241 may have it and if I had that T case I would now be heading in that direction.
This thing will do just fine if you don't get on it hard from the start. After it is moveing no problem unless you get heavy footed.
Still looking for an answer.
Denny :confused:

[Inspector]

Come on folks. You are the best. Still looking for an answer here.
Denny :rolleyes:

[Inspector]

We pulled the transfer case out last night and it looks like brand new with 131k on it. I went to the local GMC dealer and took the mechanic for a ride around the parking lot before we pulled the case. He said that the 4401 cases would sometimes brake a shift fork and sound just like that. I orderd the forks and took the case a part. The forks are in excellant condition for the miles. The Case works good also. He thought that it may not be going all the way into direct or 4hi. I took his word for that and took the case apart.
I think now that the NV4500 has the problem. We have pretty well eliminated the rest of the drive train including the T case.. :mad: