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Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: WagonWheels on November 17, 2021, 09:15:36 pm

Title: Differential/Rear End & Transmission Drive Shaft Seals
Post by: WagonWheels on November 17, 2021, 09:15:36 pm
Had seal leaks on both ends of drive shaft where the shaft meets the transmission and where it meets the rear end gear box.  There was seepage, nothing too serious.  Keith at MOT told me it wouldn't get better.  So I take it to Stewart & Stevenson (Allison) shop in El Paso to have the seals replaced.  Cost almost a coach buck.  I picked up the rig this afternoon and drove it about 20 miles to our RV park we are staying in.  Park the rig, level, extend slides, yada yada yada.  The the DW and I both notice a strong transmission oil smell coming from between the drive and tag wheels.  I slithered under the coach and didn't see any leakage, but the differential gear box felt very warm/almost hot to the touch.  Don't know if this is normal.  What say ye?  The S&S tech said that there wouldn't be much loss of fluid in changing the seals.  I had asked the question prior to the service since I had just had MOT change the rear end fluid a couple weeks ago.
Title: Re: Differential/Rear End & Transmission Drive Shaft Seals
Post by: craneman on November 17, 2021, 10:22:19 pm
Anyone who changes seals should check the diff. level after as the bad seal could have lost gear oil.
Title: Re: Differential/Rear End & Transmission Drive Shaft Seals
Post by: John44 on November 18, 2021, 03:17:46 am
Ye says you have to check the rear end fluid level and go from there,Ye also advises getting a infared temp gun to get an exact temp reading,and check the trans level.
Title: Re: Differential/Rear End & Transmission Drive Shaft Seals
Post by: bbeane on November 18, 2021, 10:15:43 am
Things should not be so hot you be smelling  them. As mentioned above check the gear oil in the rear axle, and the trans fluid level. Also an infrared temp gun is your friend.
Title: Re: Differential/Rear End & Transmission Drive Shaft Seals
Post by: oldguy on November 18, 2021, 11:09:13 am
When you say hot to the touch can you hold your hand there or is it too hot. Is it
hotter around the seal area that was changed. It could be somehow the pinion
bearings are too tight after the seal replacement.
Title: Re: Differential/Rear End & Transmission Drive Shaft Seals
Post by: Protech Racing on November 18, 2021, 02:45:47 pm
Check the diff oil and  see if you can take it back to the service place Call  . You may need some major love.
Title: Re: Differential/Rear End & Transmission Drive Shaft Seals
Post by: WagonWheels on November 19, 2021, 11:59:25 am
Have temp gun, but forgot to use it. Darn.  The gear box was very warm/hot just after I had driven the coach, but not so hot I could not keep my hand on it.  Called the repair facility and they said it was probably residual oil, but bring it in if I noticed any leaking.  I crawled under the coach yesterday to check for any leaks and found none. 
Title: Re: Differential/Rear End & Transmission Drive Shaft Seals
Post by: John44 on November 19, 2021, 05:27:16 pm
Sounds like the "residual oil" is the oil they "forgot" to wipe off after they changed it.
Title: Re: Differential/Rear End & Transmission Drive Shaft Seals
Post by: WagonWheels on November 20, 2021, 10:01:06 am
Yep, I'm hoping the smell is residual burn off.  Some research on normal operating temp of the rear end indicates it's about 190 to 210 depending on gear ratios and type of fluid used.  I'm thinking the warm/hot touch of the outside case was probably normal .  Will use my heat gun next time I travel after the holidays.  Happy Thanksgiving!!
Title: Re: Differential/Rear End & Transmission Drive Shaft Seals
Post by: oldguy on November 20, 2021, 10:51:07 am
If you can hold your hand on the differential it is not to hot. You would not be able
to hold your hand on the differential if the temperature was 190 degrees.
Title: Re: Differential/Rear End & Transmission Drive Shaft Seals
Post by: John44 on November 20, 2021, 03:34:32 pm
The only way the oil is going to burn off is if it comes in contact with the exhaust piping.