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m37 transfer case seals
Posted: Mon Jun 20, 2011 3:08 pm
by nutsfor59
hi,does anyone have current part numbers for the seals,from national or any other maker ??? thanks
Re: m37 transfer case seals
Posted: Mon Jun 20, 2011 6:09 pm
by MSeriesRebuild
nutsfor59 wrote:hi,does anyone have current part numbers for the seals,from national or any other maker ??? thanks
National 410308
Re: m37 transfer case seals
Posted: Tue Jun 21, 2011 5:09 pm
by rtkjmk
Don't forget the "REDI SLEEVES" for the yokes , or you will just ruin your new seals and they will not seal properly . The Timken # for the sleeve is 99212 .

Bob K
Re: m37 transfer case seals
Posted: Wed Jun 22, 2011 12:24 pm
by nutsfor59
hi,interesting !! never heard of that before,can you tell me more about this ??? i put a new set of seals in last year and they leak bad,maybe thats why ???
Re: m37 transfer case seals
Posted: Wed Jun 22, 2011 1:23 pm
by Cal_Gary
Companion flanges will "groove" over time where the seal edge rides against it. Likely this is your problem. The redi-sleeve installs over the companion flange and essentially provides a new surface for the seal to contact. If you don't go the redi-sleeve route you'll need new companion flanges-AB Linn has them on eBay all the time.
Gary
Re: m37 transfer case seals
Posted: Wed Jun 22, 2011 1:32 pm
by MSeriesRebuild
It is literally a total waste to install new seals of any kind without redi-sleeves. While grooving is an issue for sure, rust pits are usually a bigger problem. Installing sleeves is a better fix than new yokes; the yokes will rust readily, the sleeves are stainless steel, so rusting is not an issue.
Re: m37 transfer case seals
Posted: Wed Jun 22, 2011 5:22 pm
by cuz
Before spending my money I inspect the condition of the companion flange and if not grooved or pitted I will not throw money at something that is not needed. For example the odds of a 2 year old companion flange needing a redi-sleeve is pretty slim.
Re: m37 transfer case seals
Posted: Thu Jun 23, 2011 12:41 pm
by nutsfor59
hi,yes thats what puzzled me !! my companion flanges are all new !!!! so why would i need those ???,however i have been told that the flanges for the front and rear differentials are not available anywhere,so in that case does anyone know the timken redi sleeve number for those ????,the seals at present are leaking pretty good and are old or possibly even the originals,so i'm prepared to find a groove in those possibly,so if anyone has the redi sleeve number for those i would really appreciate it,thanks
Re: m37 transfer case seals
Posted: Thu Jun 23, 2011 2:05 pm
by MSeriesRebuild
nutsfor59 wrote:hi,yes thats what puzzled me !! my companion flanges are all new !!!! so why would i need those ???,however i have been told that the flanges for the front and rear differentials are not available anywhere,so in that case does anyone know the timken redi sleeve number for those ????,the seals at present are leaking pretty good and are old or possibly even the originals,so i'm prepared to find a groove in those possibly,so if anyone has the redi sleeve number for those i would really appreciate it,thanks
National #99187 fits the pinion flanges.
Why would you need those? Well technology has improved 60 years worth since the flanges were made for 1 thing. The surface finish is way better on the sleeve and it's stainless. You can certainly approach it anyway you like, but for a guy who had never heard of a redi-sleeve yesterday; if I were you, I'd pay attention to some experience. I'm telling you that you will get a far better, longer lasting job, with way less seeping or worse if you correctly install the sleeves; even on a new yoke. I've tried it every way under the rainbow, I'm sharing my findings with you, so you can take it or leave it. Use the sleeves and get a great job that will last and not drip or fore go them and most likely hate yourself in a short while.
If you are using the NOS leather pinion seals, it won't make much difference on that end, they will leak no matter what you do.
Re: m37 transfer case seals
Posted: Thu Jun 23, 2011 2:23 pm
by nutsfor59
hi,thanks for the advice i really mean that ,and i will take it to heart,if i hate anything it's cleaning up oil mist or drips off the underneath of a vehicle,especially one i slaved over for 2 1/2 years !! i will get the ready sleaves and do as you advise,i put new seals in last year and was unaware of all this,foolish mejust never gave it a thought,presumed new would make things all better !!,as they say "never to old to learn" thanks
Re: m37 transfer case seals
Posted: Thu Jun 23, 2011 2:34 pm
by MSeriesRebuild
nutsfor59 wrote:hi,thanks for the advice i really mean that ,and i will take it to heart,if i hate anything it's cleaning up oil mist or drips off the underneath of a vehicle,especially one i slaved over for 2 1/2 years !! i will get the ready sleaves and do as you advise,i put new seals in last year and was unaware of all this,foolish mejust never gave it a thought,presumed new would make things all better !!,as they say "never to old to learn" thanks
The bottom line is there is always a reason for a leaking seal. Sometimes, but seldom is that reason simply because the seal is just worn out; more often than not just replacing a seal does not provide a satisfactory result. Finding out the reason why the seal failed before doing the repair is a much better way to approach these issues.
Re: m37 transfer case seals
Posted: Thu Jun 23, 2011 7:38 pm
by cuz
I would like to see the documented research that substantiates a need to install a repair unit called a Redi-Sleeve on a brand new pinon shaft or companion flange. Sounds like someone has a vested interest in their sales to me. Ya'll throw good money at placing flak jackets on M60 tank armor!! I'll save those dollars for the other things I really need.

Re: m37 transfer case seals
Posted: Fri Jun 24, 2011 3:56 am
by MSeriesRebuild
cuz wrote:I would like to see the documented research that substantiates a need to install a repair unit called a Redi-Sleeve on a brand new pinon shaft or companion flange. Sounds like someone has a vested interest in their sales to me. Ya'll throw good money at placing flak jackets on M60 tank armor!! I'll save those dollars for the other things I really need.

My documented research is our experience here. I'm not telling anyone to follow it as that is up to the individual to do as they see fit. I'm just sharing the facts as I've found it to work best. Makes no difference to me the choices that are made. If you have tried the various ways of doing it as we have, feel free to share your findings also; but if you haven't tried it; I believe the saying is don't knock it until you have.
Re: m37 transfer case seals
Posted: Fri Jun 24, 2011 5:03 am
by skinnedknuckles
Just make sure that when you put the sleeves on, that they go on straight and at the right depth. You only get 1 chance to do it right. Otherwise you get to go and spend another 20-30 bucks for a new sleeve. What kind of shape are the splines in the old flanges? I would not want to throw a sleeve on a flange that has worn out splines that will leak no matter what sealant that you put in between the shaft and flange. I'll agree with Charles about how the sleeves provide a much better wear surface.
Re: m37 transfer case seals
Posted: Fri Jun 24, 2011 6:19 am
by MSeriesRebuild
skinnedknuckles wrote:Just make sure that when you put the sleeves on, that they go on straight and at the right depth. You only get 1 chance to do it right. Otherwise you get to go and spend another 20-30 bucks for a new sleeve. What kind of shape are the splines in the old flanges? I would not want to throw a sleeve on a flange that has worn out splines that will leak no matter what sealant that you put in between the shaft and flange. I'll agree with Charles about how the sleeves provide a much better wear surface.
Another trick we use is to apply a good bead of premium quality silicone to the nut flange or the flat washer just before the final installation of the shaft nut. When you torque the nut, that will press the sealant up into the splines. This will stop the oil from coming through the spline paths and leaking around the nut. Without the sealant, oil will find its way along the splines and leak regardless of how good the splines are. I also highly recommend using anearobic sealer on the redi-sleeve interior so any tiny imperfections in the yoke are sealed off as the sleeve is pressed on. Concerning sleeve depth, what we do is install the seal into position in its bore, then carefully slip the yoke onto the shaft without the sleeve; mark a reference on the yoke with a permanent marker in relation to the depth the sleeve should press to get the seal lip and sleeve in a good position, preferably in the middle area of the sleeve. Remove the yoke, seal and press the sleeve, then proceed with the final assembly. Extra time, of course, but this insures a proper, leak free installation that will last.