Ye ole transfer case woes FIXED !

[Eric's hifim37]

Hello fellow M37'ers

I test drove my M37 again today after my transfer reseal and I have some good results to share. I climbed some hills and worked (lugged) the piss out of it, ran it down the HWY @ 3500 RPMs ( love the V8 ) and then took my thermogun and did some temperature checks. What a difference with the Synthetic gear oil, the case only went to 168 degrees and the output to rearend drive assembly was at 195 degrees all this from over 250 degrees before and also for the fist time no leaks The case seemed quieter also, other readings were: Rear Diff @ 135 degrees, Trans @ 134 degrees & engine oil pan @ 190 degrees so compaired to the other items the transfer was not to far off from them !

I Pulled all yokes and installed "speedie sleeves" installed new seals not NOS from the surplus places, I mean new ones from national seal and filled the case with
MOBIL Sythetic Bearing & Gear oil # SHC-634

If you want the sleeve @ seal numbers let me know, they were kinda expensive ( oil too ) but I don't care with these results. I have the stuff to do the "center diff" mod but Tower Park is around the corner so I'll redo the rear diff later

Cheers, Eric..

 

[CGarbee]

Good news! I've gotten into the habbit of sleaving and resealing the shafts on the t-cases of any M37 varient that comes into my yard as standard operating procedure... Amazing how much difference it makes, especially if you have a repowered truck and run down the highway often.

 

[70deuce]

Eric, I would likr to request the sleeve and part numbers if you don't mind. Sounds like a great once and for all fix. Thanks

Phil

 

[Torisco]

Eric, I would likr to request the sleeve and part numbers if you don't mind. Really happy that you posted this fix.

Thank you,
Gordon Felice

1962 M43B1 Nearing restoration completion.
1971 M35A2 Beginning restoration

 

[Mike_L]

Eric,

If you would, please send the redi-sleeve info. I may be looking at doing the same thing later this year.

Also, will the synthetic gear lube you mentioned work in the transmission also? I've read so many things about using synthetic lubes in the transmissions and diffs but can't ever find any of it around these parts. I have to go to the "city" to find anything like what has been mentioned, usually the Rotella stuff.

I'm still running stock drive train components but would like to upgrade in some of the non-visible performance areas.

Thanks.

 

[CGarbee]

Numbers that I use for renewing the NP200 are:
Yoke seals - National 410308 x 4 (Double lip, double case heavy duty)
Redi-Sleeve 99212 x 4
Shift shaft seals – National 6835S x 2, Redi-Sleeve 99076 x 2

Enjoy.

 

[Eric's hifim37]

Hello all,

Sorry about not posting the sleeve & seal number last night , I was tired and had already took my shoes off

The numbers CGarbee listed are the ones I used but be ready to pay a little for the sleeves, they are around $40.00 each, I am so pleased to have stopped my leaking I feel it was money well spent..

I'm sure the Synthetic gear oil would be a major plus in all of the gear boxes and I will probally change the rest of the drivetrain to the Mobil oil I listed in the the first post here soon, I will post the temp results when I get a chance after the change.

I will post any helpfull tips on these great trucks as I discover good things, so be on the look out and also I want to thank you others for your wonderful & informative posts. I have already found some very good tips on this site so "Keep up the posting"

Eric..

 

[WCRiot]

Hello all,

Sorry about not posting the sleeve & seal number last night , I was tired and had already took my shoes off

The numbers CGarbee listed are the ones I used but be ready to pay a little for the sleeves, they are around $40.00 each, I am so pleased to have stopped my leaking I feel it was money well spent..

I'm sure the Synthetic gear oil would be a major plus in all of the gear boxes and I will probally change the rest of the drivetrain to the Mobil oil I listed in the the first post here soon, I will post the temp results when I get a chance after the change.

I will post any helpfull tips on these great trucks as I discover good things, so be on the look out and also I want to thank you others for your wonderful & informative posts. I have already found some very good tips on this site so "Keep up the posting"

Eric..

Where exactly are the leaks coming from? I don't have one of these trucks yet, but Id like to know what to look out for.

 

[WCRiot]

So was there anything special about the work you did Eric? Or was this just a basic maintenance service?
I saw that you said you bought new seals rather than NOS stuff. Anything else that might have helpped stopped the leaks?

Also, was the installation difficult? Any pictures of your work?

 

[Eric's hifim37]

Hello WC,

Yea I just wanted it to stop leaking and I have bought and installed the NOS stuff from the surplus places with no luck stopping leaks, I can say that the yokes were my biggest problem. They were pitted and causing the new seals to wear out rather quickly so the speedy sleeves saved the day plus the new seals "modern" are probally better equipped to handle the extra heat my fire breathing V8 torque causes, I never used the leather type cus I knew better right off. I think the sythetic oil is going to be a big help in the transfer running cooler because it wont foam up like traditional gear oil. I still have some weepage from the speedo hook up but it doesn't leave drips on the ground anymore so I am happy

Good luck, Eric..

 

[Eric's hifim37]

Hello all,

I did my 840 mile trip fully loaded with a radio shelter & full M101 in tow last month and I can say I had no issues at all, the transfer never leaked or got hot. I kept the truck around 3300 rpms the whole time so the synthetic oil did the trick ! I can proudly park my M37 in anyones driveway and know with confidence I will not leave a puddle of oil now
Plus I averaged around 9 MPG the whole trip, (I was expecting 5-6 due to climbing through Tehachapi grade) and I did it in 4th gear, love those 318's

Eric..