P-30 454 rear main seal replacement

[Turbodime]

Well I finally broke down and replaced the rear main seal in my '90 Holiday Rambler.  The rig has around 30K on it but sat for so long here in the AZ heat (7yrs) that all the seals and hose were toast. 

We are going on a 3000-mile trip for three weeks soon so I figured I’d get that seal changed out.  Ive did this before in trucks and cars not an RV.

What I thought should be a 4-5hr job turned into a 25.25hr job all in 115° heat.

This is just a simple write up with no pictures.

First off, the engine sits too low to the crossmember to remove the oil pan.  The engine must be raised 5-6" to get the pan out.

The drive shaft needs to come off and make sure you un-bolt it at the U-joint straps NOT the four bolts at the parking brake drum.  These bolts are not captured, and you will need to take the drum off to retighten the bolts.

The transmission must be slid back around the same distance.  The 8 bolts that hold the tranny crossmember  to the frame are easy to get out on the bottom bolts but the top 4 bolts are a pain.  There are lots of electrical lines and hoses between the coach and the frame rail.  I had to cut some Ty-Wraps off to get the bundles separated to get to the bolt heads.     Best option here is an open ended wrench on top, and a socket swivel taped at the joint, plus a couple of extensions at the nut.

Once these are removed, support the front of the tranny with a jack, then remove the tranny bolts.  Once these are out, slide back the trann.  I used pry bars and it took an hour to move, one reason was one of the upper bolts in the crossmember was left in and really went smooth once removed.

Now for the fun part.   Lifting the engine was not that bad if I had the correct tool.  The engine hoist I had was too short. I fabricated a piece of box tubing to get me the 2’ I needed.  Well, this didn’t work, as the tubing on the hoist bent.   Back to the shop and I made a nice stainless ¼” wall box tubing piece, It worked great.   I used a forklift to hold down the rear of the hoist as I was 2’ past the end of the legs and the rear was coming up. 

The exhaust didn’t need to come off, just go slow and check for any wires, tubing, hoses, grounding straps that may need to be removed or moved out of the way.

Nothing needed to be unbolted or removed to lift the engine, besides the engine mount bolts.

The rest is typical rear seal removal.

The reason for the 25 hrs was due to me not having the correct hoist.  I spent driving back and forth 30miles a couple times fabricating parts just for this part.  The other delays were fighting the crossmember and two broken bolts I had to remove plus the removing of the parking brake drum bolts.

If I did it again It would be a 8-10hr job.

Also make sure you have a torque wrench as you’ll be taking of the rear bearing cap and oil pump.

Oh, by the way, the leaks are goneJ

   

[M & J]

Really tough job. Congrats.

[Rickf1985]

I am curious why you couldn't jack up the engine from underneath and put blocks under the motor mounts? Was the transmission hitting the floor? I have a good 8" above the bell housing to the floor on my Chieftain, I must be the lucky one! I would only have to unbolt the fan.

[Turbodime]

Wow, lucky you I have like 2.5"


I could if I had enough jacks.  Motor mounts are directly above cross-member and Id need some type of spreader bar and four floor jacks.


I did find the rough idling issue.  It was purring before the seal job so I knew it was something that I did.    Spent an hour tracking down plug wires and vacuum hose.   Nothing found.   


Decided to take it for a drive and realized the tranny wasn't shifting normally. Ding the light bulb goes off.  Looked at the vacuum line going to the trannys Vacuum Modulator and it was unplugged.


Running good know.