Transfer Case Whine (1 Viewer)

Joined
Dec 21, 2012
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83
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Scottsdale, AZ
I have a 72 fj40 that I've been working on for three years. It has a 3fe engine, 4 speed transmission and a 3 speed transfer case. A Toyota mechanic rebuilt the Transfer case and mated it to the transmission for way too much money( I could have purchased a new one or Orion for what he charged). Last week I finally saved up enough to haul it to the muffler shop. When I got her home and took her out for the inaugural drive all I could hear was this incredible whine that sounded like it was coming from either the transmission or transfer case. It was so loud that I had to slow down at 40 mph because I thought something was going to break. Loud under power and decreases on coast. Louder at higher MPH and doesn't appear to get louder by RPM.

I put it on jacks, ran it and put my ear to the diff, trans and transfer. I'm 95% it's the transfer case. I've read all the posts that say once the gears are polished you can expect to never get rid of the whine. Can anyone tell me which gears usually get polished and how difficult are they to find? Any thought on whether I should try to repair or save up for a new one?

I guess it's going to be another year before I get to drive it.
 
Joined
Dec 21, 2012
Messages
83
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Scottsdale, AZ
Fresh GL-4 in both the transfer case and transmission. The oil in both differentials was also also replaced with fresh before I drove it.

Since I live in AZ, I'm thinking of putting 250W in it to see if that quiets it down.
 
Joined
Apr 4, 2006
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The whine is likely the new interface gear interfacing to the old gears in the t-case. I have the same setup, also rebuilt. It has the same problems. It sounds like an old v-drive boat. I wear earplugs if I have to drive it too far.

An Orion will be a little quieter since most of the gears are new. The real fix is a split-case.

It could be quieter if you replaced the synthetic with dino oil, but probably not too much.
 
Joined
Dec 21, 2012
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Scottsdale, AZ
Thanks Fast Eddy! That what the mechanic who built it for me thought it was also. I now live 600 miles away from him so he couldn't pull it and check for sure. Is there any other fix other than getting a new case?
 
Joined
Feb 1, 2004
Messages
254
Location
Pleasanton, Ca
I can tell you my experience........... When i bought my 40 I had the same whine as you described. Overhauled the T/C with new bearings and a thorough inspection. Ran it..............same whine problem. I told my story to a very reputable Toyota man and he said the case is probably warped. I bought another case and inserted all the same gears and bearings from mine. Whine problem totally solved.

So.... do you know the history of that T/C? Was it ever quiet to your knowledge?
 
Joined
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Scottsdale, AZ
I have no knowledge of the history of this case. I purchased a partial restoration project from someone who had also never had the truck running.

That's at least some encouraging news about a warped case. Thank you!
 
Joined
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I told my story to a very reputable Toyota man and he said the case is probably warped. I bought another case and inserted all the same gears and bearings from mine. Whine problem totally solved.

Damn. I carried around an extra 4-speed t-case housing from swap-meet to swap-meet for a couple years. I believe I finally gave it to Mudrak so I didn't have to carry it around anymore.

So.... do you know the history of that T/C? Was it ever quiet to your knowledge?

Mine was noisy when I got it from a reputable forum member. No knowledge prior to that, but his rig was pretty big, SOA, 35s. He swapped this case out for an Orion.

Great. Yet another project. FML.
 
Joined
Aug 26, 2007
Messages
1,039
When they rebuilt the TC did they replace the idler gear shaft? Mine was pretty loud, replaced the idler gear bearings and shaft and is now quiet.
 

brooklyn

SILVER Star
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May 11, 2007
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Wow, i feel for you. i had a transfer case rebuilt hoping to lessen the whine., which didn't. Sold that FJ40/1972 and then purchased a 1968 FJ40 that the whine, but to a lesser degree. Heavy weight oil did lessen the noise for me. i had other FJ40 owners in the truck and they have said the noise is not that bad, but i think the whine is a noise that just gets to me. You may want to pickup tcase used and swap that in and see if its any better.

i am currently putting a split case in, which is not a direct swap and there are a few good write-ups if you search the threads. This part of an engine/trans/tcase swap project.
 
Joined
Jul 24, 2015
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1
Location
Benton City WA
Regarding the whiney transfer case stories I've been following I'd like to add my 13-year experience trying to find a fix for my '73 FJ-40. Everything was quiet and fine until I decided I needed a 285 hp Chevy 350 in front of a 700-R4 trans. That was in 2002. I used an Advance Adapter kit between the 700-R4 and the early TC... First time on the road..."WTF".... horrible whine like I've never had and always under load. The TC was 100% rebuilt including the idler shaft and needle bearings/shim/spacers. My reference manuals were the original Toyota Shop manual and also a Haynes manual. The thrust clearances for the idler gear from the two different manuals are very close and were set up accordingly... (.013')

I have questioned weather the Toyota manual had an error in it when it showed a spacer and a thrust washer behind the small idler gear at the rear of the TC and only a T-washer in front of the big gear at the front. This set up is shown the same way in the Haynes manual.... My initial logic was the whine was caused because the two gears are running too DEEP with respect to each other.... a common occurrence with incorrectly set up gears.

Fast forward to 2003. I pulled it all out and found damage to the idler shaft (spauling) a small area aprox .100" x .200" where the shaft is giving up metal... not good! I replaced the entire TC gear set (4 gears) and put in another idler gear/needle bearing set. Thrust set at .007" this time... I added a pint of gear lube additive for good measure "Power Punch" with a Moly-disulfide base for superior wear resistance... still got the whine!...

Very depressing... I know lots of you guys have been there and I really appreciate all of your inputs.... thanks in advance. So essentially the rig hasn't been driven much... fire it up once/month and drive it 1/4 mile to the end of the road to get the mail!

So I decided to give it another go now and it's on the floor again. My plan now is to experiment with different thrust settings of the idler gear and check how those settings affect the backlash (if any) between the two gears. I can also check the mesh between the gears using some Prussian blue/white lead on the gear teeth faces just as in checking a ring/pinion set up... I'm also considering making these checks using the old 3 spd set up.

The most disturbing thing is that the TC was QUIET B4 all this started.... what the Hell did I do?....

Thanks, Pete
 

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