Diff oil in tranny, how to fix?

[RalphM]

AV8 has been getting overfull tranny, diff is low. It's a 37 tranny and rear axle, but I shortened the tube, took out the center bearing and put in a 34 style hollow driveshaft. Now it's got a little bit of rake, so I'm assuming this is allowing fluid to move forward. Does anyone make a seal that I can put back by the diff to keep the oil in it?

[john in illinois]

I haven't used this but had it in my files.

http://brucesrodshop.myshopify.com/c.../hot-rod-parts


John

[RalphM]

Looks like it would work, but it will change the driveshaft length if added to a torque tube, these may be made for open drives. I'll stop by there and talk to them next month. I'm going home for Christmas and Bruce's is close by, I've been there before, good folks, gave me a tour last time I was there.

[Terry,OH]

It doesn't lengthen the torque tube enough to cause any problems, and it works.

[weldor2]

Does anyone make one for a Model A rear ?

[RalphM]

Sponsored Links (Register now to hide all advertisements)

I shortened my torque tube to fit the 32 frame and the place I had cut my drive shaft cut it a little short. so when I put it together the C clip that holds the speedo gear in place was very tight. I'm afraid any longer and I will have to shorten my torque tube or lengthen the driveshaft.

[deuce_roadster]

You can park your car when in the garage with the front wheels on those ramps they make. It will drain back.

[OHV DeLuxe]

With the stock seal in the front of the torque tube just behind the roller bearing, i don't see how the heavy rear oil can go past that?

[RalphM]

Originally Posted by OHV DeLuxe

With the stock seal in the front of the torque tube just behind the roller bearing, i don't see how the heavy rear oil can go past that?

Me neither, but it does. I put the car away for the winter about a month and a half ago, just pulled tranny fill plug yesterday and it was almost a quart over full.
Pulled diff fill plug and it was low. Maybe I can run a tube from the front to the back, with a check valve to let the fluid circulate back.

[32phil]

There are several other posts on the Barn covering this.
The short version is ....with a "rubber rake" the diff. fluid wants to flow towards the trans down the torque tube. Stock Early V8 rears have a seal at the trans end of the torque tube, about 6-8 inches or so in ....
if that is worn/missing it will leak towards the trans. I have two cars with exactly the same running gear/rubber rake. One is fine the other fills the trans.
I put a new seal in one and.... forgot (#$%^%$#) to put one in the other...
guess which one leaks??.......
It's a chore to do now cause the whole rear has to come out.....
a project for next spring.

[V8COOPMAN]

Originally Posted by OHV DeLuxe

With the stock seal in the front of the torque tube just behind the roller bearing, i don't see how the heavy rear oil can go past that?

That seal is only designed to work in one direction, and that is to keep trans lube from migrating rearward. DD

[Tim Brown]

I was having the same problem. The ring and pinion work just like an oil pump moving fluids forward into the torque tube. I put the Bruces rod shop seal in my 34 roadster last summer. It rides on the driveshaft/pinion coupler. The first seal was too tight (not bruce's fault) and burnt up quickly. Once I looked up the inside diameter spec for the replacement seal, I machined the OD of the coupler to the right size and reinstalled it. It worked this time. Another consideration, if you are running a hollow driveshaft, it can also fill up with gear lube, which mine did. That created some whooping sounds at higher speeds. I used a bunch of permatex on the coupler splines this time around the try and prevent my driveshaft from filling with lube again. It didnt change the length of my torque tube to make any difference. You guys know how much work it is to pull the rear end out 3 times in a row? I think you do...

[19Fordy]

Tim, I have to give you lots of credit for your persistence. Pulling a rear 3 times is NO FUN. I ordered one of Bruce's seals but don't look forward to the installation task. I also plan to install new bearings and seals inside the torque tube. Is it possible to install Bruce's seal plus new seals and bearings inside the torque tube without removing the rear splined coupler? I have never taken my 40 rear end or torque tube apart. Thanks, JIM

[OHV DeLuxe]

Originally Posted by V8COOPMAN

That seal is only designed to work in one direction, and that is to keep trans lube from migrating rearward. DD

Ok, i put it in with the lip inwards so it will keep oil in there, and put a bearing in the rear of the trans with a seal on one side.

[Terry,OH]

If you are using a splined coupler to the pinion why not redrill the hole for the pins about 1/2" outward this would lengthen the drive shaft and coupler combination and you don't have to lengthen the drive shaft. Usually the speedo gear has about 5/16" free play to the clip ring.

[RalphM]

Seems like the seal at the rear diff is the better idea, because the tube would still fill up even if it didn't get to the tranny. Like I said they cut my driveshaft a little short, so I almost didn't get the C clip to go in there, I like the setup Bruce's sells, but it may cause me to machine a little off the torque tube flange in order for it to go back together well.

[my4dv8]

Sea bright hot rods make a seal system, vern Tardell used to make a dam type seal also.
As a bandaid we put an overflow from the filler plug into a catch can with a small float switch inside attached to a pump capeable of moving hot oil . So every now and then the pump starts up and returns the oil back to the diff. Messy but it worked well for several 1000 Mls. Till we went to open drive.
http://www.seabrighthotrods.com/?p=522