[matty_wall]

Hey all.. I have a 92 sierra with NT centres and flanges. Is it ok to run a mix of WT and NT shafts up with out any consequences? I have been driving my car with this set up since I got it and I have some vibrations coming through the car above 90k's, the vibration is not coming through the steering wheel any where near as bad as its coming through my seat. I have replaced gbox and engine mounts. Tcase mounts look ok. Wheel bearings and king pin bearings are new. unis seem fine. There is a few mm of play in the rear shafts spline and the shafts are all in phase. Is there anything else that could be causing this?
I wanted to avoid changing the flanges as I understand that the crush tube behind it has something to do with pinion position or something like that and ive never fooled around with a diff centre before.
Hopefully that makes sense to someone

Matt

[want33s]

You can fit NT flanges to your transfer or go and get your half/half shafts rebalanced.

[matty_wall]

If I go down the NT transfer path. do I have to Install the Transfer hand brake or will one of the other flanges off a NT transfer fit the rear?

[want33s]

From memory the input and rear output are same but front output is different.
So if I'm correct you could fit an NT input flange to the rear output shaft.

Not 100% about it though and don't have a transfer to go and check.

[matty_wall]

Ive got a NT transfer at my uncles place so ill check it out this arvo.

Thanks!

If it doesnt work out, how hard is it to swap the diff centre flanges? can I just count how many times the flange bolt turns and tighten it the same number of turns when I put the WT flange on?

[BlueSuzy]

The rear output flange is longer than the input/frontoutput.

I think i have some here matt if you want them. Off my transfer on my shelf. Will be in riff on sat nite

[2stroker]

If you have used half a WT shaft and half a NT shaft make sure they are indexed or that could be your vibration. i.e. that when you sld them together the original dots (index marks) lined up exactly.

[matty_wall]

2stroker wrote:

If you have used half a WT shaft and half a NT shaft make sure they are indexed or that could be your vibration. i.e. that when you sld them together the original dots (index marks) lined up exactly.

I had no idea about about those dots.. I just thought the unis had to be in phase. ill check that as well.

[matty_wall]

Where abouts are these index marks 2stroker? i'm have trouble finding them.

[Jackson]

There is little dots on the female end of the spline it is on the oudside near the end and on the male part it is on the end of the shaft. I think.

[matty_wall]

Ok heres some marks I found on the male end. I cant see any marks of any kind on the female end.

[2stroker]

Sorry mate my camera is at work or I would take a pic, you are right about being in phase however 1 spline out can look OK. The marks are like a factory pin punched mark on the outside edge of the female and on the end of one of the splines of the male

[matty_wall]

2stroker wrote:

Sorry mate my camera is at work or I would take a pic, you are right about being in phase however 1 spline out can look OK. The marks are like a factory pin punched mark on the outside edge of the female and on the end of one of the splines of the male

When I set the shafts up I lay the flanges on flat ground to make sure they are straight so they should be right. Ill pull it out tomorrow and check for these marks. cheers mate

[matty_wall]

OK I've found the punch mark on the male end, but i couldn't find a corresponding mark on the female end. Bluesuzy is getting me a NT flange for the rear transfer output anyway so hopefully this will be sorted soon enough.

Matt

[BlueSuzy]

Oi check your stalkbook inbox

[want33s]

[johnmath]

Quote:

Ok heres some marks I found on the male end. I cant see any marks of any kind on the female end.

The male end seems to be rather small in this photo...

[steve]

maybe try taking the rear shaft out and drive around in front wheel drive to see it vibrates the same.

[2stroker]

steve wrote:

maybe try taking the rear shaft out and drive around in front wheel drive to see it vibrates the same.

If it is like most sierras it will vibrate in 4x4 with rear shaft out because you have made it into a "V" drive and you are putting torque stresses on the transfer mounts that they are not designed for. In 4x4 with both shafts fitted they kind of compensate for each other and in 2wd it is fine because the transfer mounts are designed for rwd.

[steve]

i'd still try it. I know someone that removed the rear shaft and drove around for a few weeks. Steering will be a bit awkward but it could provide some answers.

I had vibrations once and found it to be a bend transfer case bracket.

[matty_wall]

OK, the rear shaft is in phase and indexed correctly.. took it for a spin with the rear shaft removed as well, vibs were exactly the same at 90k's and up. I actually got an extra vibration at 40k's as well haha. me thinks something else might be at play? the transfer arms look fine as well.. i cant see any signs of them being bent.

[want33s]

Check your wheels to see if you have lost any balance weights.
Jack up and spin each wheel to check for buckles.

[matty_wall]

All balance weights accounted for and no buckles. the wheels should be fine anyway. I ran them on my vitara with no issues and this vibration has been there since i first drove the car.

[want33s]

matty_wall wrote:

All balance weights accounted for and no buckles. the wheels should be fine anyway. I ran them on my vitara with no issues and this vibration has been there since i first drove the car.

OK.. I like to eliminate the easy fixes first.