New diff gears now tranny noise???

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

   So I put new front and rear 4;56 gears with limited slip front and rear. It was done by the most reputable place in town. They only do diffs... Thats it.

Any way after getting it back it seams to have a rattle/ grinding noise coming from the tranny when in 4 or 5th gear only. It runs fine... No sticking in gear, shifts smooth, no problems.... Just now have a pretty loud noise coming from it in those two gears only. I did new a new rear yoke and U joints while we were there. It kind of feels like there may be a tiny bit more vibration when running. Will it all get smoother with time? Jeep is on 37s with the T5 tranny. I do have a NV3550 I have put aside for the future. But I was going to do that during a 360 swap i have planned. Any ideas why the gear change would cause the new tranny noise?

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
terryhillman Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 14 Dec. 2020 Location: United States Status: Offline Points: 4	Post Options Post Reply Quote terryhillman Report Post Thanks(0) Quote Reply Topic: New diff gears now tranny noise??? Posted: 22 Dec. 2020 at 3:03pm
	So I put new front and rear 4;56 gears with limited slip front and rear. It was done by the most reputable place in town. They only do diffs... Thats it. Any way after getting it back it seams to have a rattle/ grinding noise coming from the tranny when in 4 or 5th gear only. It runs fine... No sticking in gear, shifts smooth, no problems.... Just now have a pretty loud noise coming from it in those two gears only. I did new a new rear yoke and U joints while we were there. It kind of feels like there may be a tiny bit more vibration when running. Will it all get smoother with time? Jeep is on 37s with the T5 tranny. I do have a NV3550 I have put aside for the future. But I was going to do that during a 360 swap i have planned. Any ideas why the gear change would cause the new tranny noise?

Stev Members Profile Send Private Message Find Members Posts Add to Buddy List Member Sponsor Member Joined: 27 July 2016 Location: Cincinnati Status: Offline Points: 2391	Post Options Post Reply Quote Stev Report Post Thanks(0) Quote Reply Posted: 22 Dec. 2020 at 3:21pm
	Welcome to The CJ2A Page. It sounds like you have a pretty modified Jeep. Grant it, most of us are old Jeep guys here - Flat heads, stock or stocker locker type drive lines. So take what we offer with some coffee or whiskey. My guess is that the drive shaft is the issue related to the vibration. The yokes should be in the same plane on the front and rear side of each shaft - not 90 degrees each other. The splines on the shaft could be worn (no lash is what you want) or the shaft could need to be balanced (assuming thing happens at high speeds (4th &5th gear). Did they put the friction modifier in the front and rear differentials? If not the limited slip clutch packs will make noise. You could drain the differentials and refill them making sure they have the friction modifier added this time. This is a cheap solution that might fix that issue. Let us know what you find.
	Stev 1946 CJ2A Trail Jeep (The Saint), 1948 CJ2A Lefty Restored

duffer Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 02 Feb. 2012 Location: Bozeman, MT Status: Offline Points: 1088	Post Options Post Reply Quote duffer Report Post Thanks(0) Quote Reply Posted: 25 Dec. 2020 at 1:57am
	Did you have driveshaft alignment shims on the spring perches? Did they get reinstalled on the proper axles? There should not be any connection of axle gear swaps to increased transmission noise-unless perhaps there is play in the transmission output bearing. Poor driveshaft alignment would definitely acerbate that assuming there is no transfercase in between. Is this jeep still 4x4?
	1955 3B: 441sbc,AGE 4 speed transmission, Teralow D18w/Warn OD, 4.11:1 D44's/ARB's, glass tub & fenders, aluminum hood/grill, 8274, York OBA, Premier Power Welder; 67 CJ5: 225,T86AA, D18, 4.88's, OD