Transmission noise.

[jb8376]

I have a noise in my Transmission or somewhere in the driveline i cant figure out. All ujoints, wheel bearings, clutch flywheel pressure plate etc. Is new. The Transmission is completely rebuilt. I have had it out 5 times now and can't find it. The noise only happens while coasting , the Transmission is in gear and the clutch pedal is pushed in. I do have a new 2.5 lift, and 1/2" lift in shackles. Ive installed a new double cardan driveshaft also. The only thing i havent touched is the Transfer Case . I dont think the noise is from there but i have a friend who has an extra that he is going to let me borrow. I will install his to rule that out. Any suggestions? Any help would be greatly appreciated. Below is a link for a you tube video of the noise.

https://youtu.be/b_5heV45PaQ

 

[Lumpy Grits]

What tranny? The T-4 ??
Look at the clutch pilot bearing and your T/O bearing.
What oil are you using? If T-4 -run 75W90 syn. syncomesh only.
Dana 300 t'case, use 80w90 std gear oil.
LG

 

[jb8376]

Yes it's the T-4 . New pilot bushing and throw out bearing. I tried the synchromesh in the beginning. Now I have Amsoil 75w 90 GL-4 gear oil in the T-4 and 80w 90 in the 300.

 

[Lumpy Grits]

When was the last time you greased the u-joints and slip splines in both DSs?
Who's clutch are you using?

LG

 

[jb8376]

Greased just recently. The rear shaft is new. It's a LUK clutch set. During one of the many times I had it out I even put the old clutch and pressure are back in thinking it might be the new clutch. I have driven it around with just the front and just the rear drive shaft and it does it either way.

 

[Lumpy Grits]

Also-How much clutch pedal freeplay(travel)do you have?
You want no more than 1 1/4" and no less than 1".
When it makes this noise-what happens if you slide the tranny shifter back and forth in neutral?
Can you feel anything through the tranny or t'case shifter?
Who rebuilt the tranny?
LG

 

[hagar]

Sounds wheel speed related to me, not drive line.
Almost like a tooth is missing.....somewhere.
Might pull the rear cover and have a look.

 

[mtnwhlr]

Will it do it when up on jack stands? If so climb under and pinpoint where it's coming from.

 

[jb8376]

Also-How much clutch pedal freeplay(travel)do you have?
You want no more than 1 1/4" and no less than 1".
When it makes this noise-what happens if you slide the tranny shifter back and forth in neutral?
Can you feel anything through the tranny or t'case shifter?
Who rebuilt the tranny?
LG

I have the free play set up right at about 1 1/4. The noise happens in any gear even reverse but goes away when you shift to neutral. I don't think I can feel it in the shifter but I would have to double check. I had a reputable local guy rebuild it and he has opened it back up and doubled checked everything. I also have opened it and replaced all small parts and double checked everything. The throw out bearing does seem close to the pressure plate but I think it is about a 1/16th off of it. The new fork boot seems stiff not letting the spring pull it back.

 

[jb8376]

Sounds wheel speed related to me, not drive line.
Almost like a tooth is missing.....somewhere.
Might pull the rear cover and have a look.

In will definitely give that a look. The sound sure seems to be coming from the tranny area.

 

[jb8376]

Will it do it when up on jack stands? If so climb under and pinpoint where it's coming from.

I haven't tried that. I might have time tomorrow. I'll report back.

 

[Lumpy Grits]

I would also take the time to pull the read diff cover and closely inspect the ring gear and pinion. Also see what is in the bottom of the case........
LG

 

[jb8376]

I put it up on stands and listened to it. Sure sounds like it's coming from the front of the tranny or in the bellhousing. I have driven it with just the rear shaft and just the front. There was no change. The sound was still there. I would think that would eliminate the front and rear diff. Also the sound goes away when I shift it into neutral and I'm still coasting. So the shafts are still turning.

 

[Torxhead]

Finding the exact location of a noise can be a rear bear. A stethoscope might help here. Noise does travel thru metal pretty good though.

 

[Lumpy Grits]

Again I'll ask-
What happens to the noise, when you move the tranny shifter side to side in neutral?
What do you feel in your had via the shifter, if anything?
What happens when the t'case in in 4HI?
LG

 

[jb8376]

The noise completely goes away when I move the shifter into neutral even when I move it side to side. I can slightly feel it in the shifter. The noise is there in 4Hi and 4LO. It goes away if I pop the Transfer Case into neutral.

 

[Lumpy Grits]

When you had the tranny cover off-
Did you inspect the shifter forks at all?
Did they have the 'pads'?
LG

 

[jb8376]

When you had the tranny cover off-
Did you inspect the shifter forks at all?
Did they have the 'pads'?
LG

Yes and I put new pads on.

 

[Lumpy Grits]

I would ck again.
with the cover off. You could also look/feel for slop/play in the main & counter shaft.
I do wonder what the end-play was set at for the input shaft.
I set them to '0' end-play and add a .005 shim.
LG

 

[jb8376]

I would ck again.
with the cover off. You could also look/feel for slop/play in the main & counter shaft.
I do wonder what the end-play was set at for the input shaft.
I set them to '0' end-play and add a .005 shim.
LG

I have had that cover off 4 times now. Everything looks tight. I set the end play for the input shaft per the factory manual which says .001-.005 over 0 end play. The shims I used came to about .004. It shifts smooth in all gears.

I installed another T case today. Noise is still there. I guess that rules it out.

Here is a link to another video. Not sure if this is normal. I'm looking through the hole for the clutch fork in the bellhousing. You can see the clutch moving.and rattling around. The Transmission is in gear and the clutch pedal is pushed in with a board. The rear wheels are jacked up and I'm moving a rear wheel with my foot.

https://youtu.be/hoQML-cMEcM