M818 transmission rear seal - Steel Soldiers::Military Vehicles Supersite

bassetdeuce · 06-21-2009, 00:32

I couldnt find a TM for the 5 ton transmission, 6353 spicer? I need to replace a leaky rear seal so could someone tell me if Im on the right track?

1. Remove the short drive shaft that goes from the transmission to the transfer by removing flange bolts on both ends.
2. Take cotter pin and nut off the output shaft.
2. Remove companion flange off of the transmission with a gear puller.
3. Remove the the bolts holding the bearing cap and remove bearing cap and gasket.
4. Tap out the old seal from the bearing cap.
5. Tap in new seal.
6. Reassemble with a new bearing cap gasket.

Is this correct or am I missing something?

rosco · 06-21-2009, 00:45

Your right on.... A couple of comments though. You may, or may not have to remove the bearing cap. In some applications, and or, some Guys will just pry out the old seal and replace it with a new one. In some trannys, there will be a stack of shims under the bearing cap. You just have to be careful of them. A second thing is that the flange that you took out (where the seal lip rides), may be grooved from wear. If so, two options: Replace using a speedy sleeve, or seat your seal at a slightly different depth, so you have a good wear surface. Many shaft seals for line-haul trucks just come with a speedy sleeve anyway. Get the seal out & take it to a heavy truck store, and they will fix you up.

Lee in Alaska

73m819 · 06-21-2009, 00:45

mite not have to use a puller on the companion flange, the shaft is splined, on trans that i had to pull the u-joint yoke, it came off real easy once the nut was off, when you put it back to gether be sure the nut is touqued right, there is no tm for the 5t trans that i have seen, page 8-18 in tm 9-2320-260-34-1 covers this

doghead · 09-15-2010, 20:59

Does anyone know if there is a National Seal number, or other brand name seal, that fits this application?
5330-01-023-0269 12470105 SEAL,PLAIN

The companion flange nut torque spec is 500-550ft/lbs

I am going to have to change the trans output seal on my M818, when I pick it up soon. I want to be sure I have what I need, along with me.

crasheej · 09-15-2010, 23:02

I take mine to the machine shop and have them metlize it . I've tried thr speedy sleve is a cuick way to get you down the road. Won't take lpng for the new seal run that grove in there again. The ones i've had metalozed I 've never had the grove again. I've done it to cranks, flang,just about any place that they can machine. But you can do it your way.

Ord22 · 09-15-2010, 23:03

great reading roscoe!

73m819 · 09-15-2010, 23:57

If the speedy sleeve is done right, it wont regrove, I have been using speedy sleeves for at least 30 years. the reason most sleeves regrove is that the old grove is not FILLED. use hardening epoxy. sometimes it is not possible to metalize or the heating will call for a retempering. the biggest sleeve I think I ever used was about 18", this was for a crusher shaft, the darn thing lasted past at least one rebuild , if not two, until the shaft had to be replaced for other reasons. I have used sleeves on everything from rear axle spindles to crank snouts, from D9 trans input shafts to crusher shafts. like anything else, if its done right, it will last, if not it wont

As a side note, there is usually a reason a seal dies
1--sat for a long time, it dried out (no lube on it) then got used and got burnt
2--sat for a long time and the rubber rotted
3--bad bearing allowing the bearing surface to move out of contract with the seal surface
4--dirt from the outside or debris from the inside

doghead · 09-16-2010, 07:45

In this case, the transmission looks to be new. The whole truck seems to be a depot rebuild with new parts and paint.

I am guessing that my seal is leaking from sitting so long(hope more seal do not become an issue).

Possibly the seal was damaged on installation. Maybe the transmission is extremely over full? Maybe the coupling has a groove worn in it?

All I know right now is, the truck was driven about 15 miles and is quite wet with oil on the rear of the transmission. It appears to be coming from the output shaft seal.

cjtroutt · 09-16-2010, 08:13

Hay Doghead some times they used Synthetic oil after referb L3 use to do this and we would have leaks all over the place.

crasheej · 09-16-2010, 12:01

Ron your right about filling the grove ,but most people don't know that and no one tells them that. still if I can I metalize. Ernie