Transmission Options

[rayhawk]

OK, think I've got it figured out. The noise is coming from the transfer case, seems like it tries to engage the front driveshaft when it's not supposed to. Also, I went to pull the fill plug, and a ton of extra fluid came out too, so I'm thinking I'll rebuild the whole thing.

transfer case noise

Hopefully it's not too difficult to overhaul it.

 

[NickTransmissions]

OK, think I've got it figured out. The noise is coming from the transfer case, seems like it tries to engage the front driveshaft when it's not supposed to. Also, I went to pull the fill plug, and a ton of extra fluid came out too, so I'm thinking I'll rebuild the whole thing.

transfer case noise

Hopefully it's not too difficult to overhaul it.

Not sure if this is so in your area but out here (Vegas), GM 90s and early-mid 2000s transfer cases are everywhere in junk yards, just laying around. Think they get $100-$150 for them. Most are ready to bolt in and go (people needing the trans or engine pull and set then aside). May be easier to grab one to get back on the road then rebuild yours at your leisure..

 

[Laredo1307]

Does sound like a starter making contact with the flywheel lol. Maybe try puling that and seeing if the gear is not retracting all the way.

Otherwise I would guess it's in the torque converter area based on the sound. Sounds loud and hollow like it's coming from inside the bell housing. I would think the transmission would sound more muffled.

Not sure you would here a sound with a "cracked sun shell". The weak point on the sun shell is at the weld interface between the spline and actual shell. Usually if it cracks the whole spline separates from the shell and at that point the transmission would most likely go into "limp mode". You would only be able to drive around in 1st-2nd gear. If you had it in 3rd or OD the transmission would slip as soon as it tried to shift out of 2nd.

 

[Laredo1307]

Just saw your last post.

If you have a ton of fluid in your T-case then it maybe leaking from the transmission. There's a seal that separates the two and if t leaks the fluid from the trans will flow back into the transfer case. There's a TBI out there about this issue. I had a shop here in Houston that damaged that seal after a rebuild and the transmission would slip as it went around curves from the fluid flowing back into the T-case.

 

[NickTransmissions]

Just saw your last post.

If you have a ton of fluid in your T-case then it maybe leaking from the transmission. There's a seal that separates the two and if t leaks the fluid from the trans will flow back into the transfer case. There's a TBI out there about this issue. I had a shop here in Houston that damaged that seal after a rebuild and the transmission would slip as it went around curves from the fluid flowing back into the T-case.

For clarity, the seal is on the Tcase input not the transmission. The 4L60Es and 700R4s dont actually have a seal, just the rear case bushing which mostly seals off the transmission case from the ext housing/tcase adaptor..the 4L80Es and 6Ls do have a rear case seal but the 700R/4L60Es dont...so an excessively worn rear case bushing may allow trans fluid to leak past and collect in the ext housing. If the tcase input seal is also bad, trans fluid will flow into the tcase...

 

[rayhawk]

Got the transfer case out today, and mostly taken apart. The circlip on the output shaft failed, and allowed the shaft to move. Spit out some of the synchro keys and what I think is the synchro hub spring. Will finish taking it apart tomorrow and assessing the damage, hopefully nothing was damaged when the spring went for a tour inside the case.

 

[rayhawk]

Got it all back together, back on the road finally. So far so good. I did find out that there is an aftermarket upgrade for the output shaft retaining clip from Sonnax, so hopefully this doesn't happen again.