Engine/Transmission (1994 - 1998) Transmission removal question

[JGheen]

Well, I am trying to get all the info needed for replacing my clutch soon, as my new SBC con OFE Oo. is arriving tomorrow and I was just wondering about some things.

Do I need to support the back of the engine somehow when removing the transmission or is there enough support to hold it up and balanced by just the two engine mounts on the driver and passenger side frame rails? I am going to be tearing into this project myself for the first time as I am gonna need to learn how to do it someday and I am tired of leaving these type of big projects up the dealer$hip. I have done transmission, clutch, t-case, etc. swaps in early Chevy trucks before(most of my experience) and have been gathering all the info I can for this swap and couldn't find anything on engine support while the transmission is out of the truck.



Also, I was considering purchasing the cast iron transmission/t-case adapter from Standard Transmission to replace the stock aluminum one, is this really a wise purchase with the SBC upgrade or is it not necessary?

And any other tips or short cuts for this job would be greatly appreciated as well.



Thanks a lot guys, Joe

 

[onestackdram]

no don't worry about it, it will hang there just fine we pull them out all the time and it will sit there just fine. If you want to you can brace it up a little after you get the transmission out, but that would be just for your ease of mind. Other than that there is nothing to it it's just like any transmission pull you can do on a manual. there really aren't any secrets or tips, just get a good transmission jack and pull the t-case first, and then tackle the transmission seperately, yes they can be pulled together but I reccommend seperate just for the ease of less to worry about at one time.

 

[JGheen]

Thanks!



Yeah, I have read all the threads on trying to remove the transmission/t-case as one and I am definately going do like the others and pull the t-case first.



Oh! Got another question along with the above adapter question.

Is it a good idea to replace the rear main seal if it shows any sign of leaking since I will be installing my new flywheel with the clutch? If so, are there any tips to replacing it?



Thanks again, Joe

 

[onestackdram]

Always change the seal if it shows leakage, although I don't think I have seen 1 in the last 20 or 25 trucks we have pulled transmission's on that had a leak, but yes always check. If it does need to be changed that is not something a weekend warrior should tackle. A fairly knowledgeable mechanic hates doing those in when the engine is still in the truck let alone someone who doesn't do much in turning wrenches.



First of all you will HAVE TO HAVE a seal driver to put the new one in or it will NEVER be right, and to make matters worse they are specific on the driver used, because they have to be certain depth, and be perfectly straight in the crank bore in the block, and don't let anyone tell you other wise. I would reccomend that you let someone who knows what they are doing do it unless you feel 100% confident that it is in your realm of knowledge and ability

 

[JGheen]

So, where can I find this specific seal driver? Is there a specific seal puller as well for the job?



Also, do you have an opinion on the cast adapter from Standard Trans?

 

[onestackdram]

As far as I know there really isn't a seal puller so to speak, other than trying to pry it out with out damaging anything... LOL... . thats the part no one likes.



I have no experience with the cast adapter so i will let someone else comment on that

 

[CumminsPower98]

From my experience (1 '97, 1 '98 and my '98 many times) I find that it makes things a bit easier to actually jack the front of the engine up slightly to get the transmission angle right so it comes out without hitting the firewall. Of course this is with a 6 speed. By default the engine actually tilts forward when the transmission is removed so no support is needed under the back.



As for the seal, I have replaced 3 of these things in different trucks and it's not that hard. The seal comes with a steel driver/alignment tool, at least the National seals do. I have never used a Cummins seal. I personally took the little aluminum housing the seal fits in off of the engine to do the job so I could do it on the bench and make things easier. It can be done on the truck too but its not as easy this way.

 

[JGK]

JGheen,



A friend of mine and I just replaced the clutch in mine last weekend. First time for both of us (though he's pulled his auto transmission 4 or 5 times in his '98 tweaking with it).



I'd jack up the front end of the engine just to get a little better clearance for R & R. Otherwise, it tips down in front and lining up the transmission for reinstall might be a bit more challenging.



We left the transfer case connected to the transmission. Borrowed a real nice heavy duty transmission jack and put it directly under the transmission, but put a big floor jack under the back end of the transfer case for good support. That gave us a lot of control to tip the assembly for better line up on removal/re-installation.



We also drove the truck up onto ramps under the front wheels (only) to give us an additional 6" of clearance. Made it easier to work on.



Everyone claims to have to spread the frame to get the cross member out. We just jacked up the transmission a few inches using the jack under the transfer case (after removing the drive line - and don't have the support under the front of the engine at this time!) and pushed the cross member up, then FORWARD. It dropped right out. Have to tilt it a little, but it worked. Most move it backward, but that seemed to us to be a lot more work.



Did not replace the rear case seal. No leakage indicated.



One last thing, two sets of hands are better than one. I would not have done this alone. Now if I'd done several, then probably...



-Jay

 

[JGheen]

Thanks guys,



I won't be needing to jack the truck up any as there is plenty of clearance for me to get under there and remove the transmission with 7" of lift and 38" tires.



I will definatelty take your advice and put a block of wood on my floor jack and put some support on the front of the engine to keep it from dropping forward some and making things difficult when taking the transmission out.



JGK, I have heard of the spreading the frame theory as well, but from the looks of mine I should have no trouble removing it once the t-case is out and the transmission is jacked up some. Did you say you had pulled your out FORWARD as in towards the front of the truck?



Anyone with an opinion on going to the cast adapter from the stock aluminum one?



Joe

 

[BHigby]

Just replaced the rear main and clutch a week ago. I pulled the transmission and t case out as one unit. i had a friend help steady the transmission on a floor jack and the job went fairly easily. I unbolted the cross member from the transmission and pounded it out towards the front of the truck one side at a time. As for the rear main seal, i got one from cummins and it came with the seal driver. They said to pull the seal with a slide hammer, but it can be done with a small screwdriver. Installation of the seal is simple and the directions show exactly how to do it. This whole job is not so bad as long as you have an extra set of hands.

 

[JGK]

Yep. FORWARD! As you've read by now, the frame is tapered so that the cross member won't come straight down. You have to pound it up against the floor pan, then move it fore/aft. Just aft of the tapered area is some additional metal on the inside of the frame (on mine anyway) that makes it just about as tight. So after fussing with it for several minutes we decided to go forward with it. Once it's past the tapered area and you start to bring it down you have to rotate the bottom back a bit, but it wil slip out. Just forward of this area the frame begins to narrow so you don't have a lot of extra room. But two of us laying on our backs, one on each side of the truck, had no problem wiggling it out with a few moderate whacks with a rubber dead-blow hammer.



-Jay