Combining 2 '91 xlt manuals

[EastoutWest]

I've had these two '91's for about a year now. My goal has been to take the best from each and build one reliable fun/work machine.

Here's the skinny:

- Red one is my daily driver - it's a 91 XLT with m5od and electric 4wd/auto hubs. It has a rust problem (probably driven on the beach for years) and is quite beat up with probably 250k miles and sloppy steering/suspension components. It runs pretty well and the transmission is just fine, but the truck itself is pretty much falling apart from the rust and body damage.

- The blue one is on jack stands. It is also a '91 xlt with the m5od but with manual t-case and hubs. Also has factory towing and limited slip, no significant rust, runs very smoothly and has very little play in the steering. But the transmission is destroyed.

I removed the trans from the blue one and opened it up. One of the main gears was stripped clean and metal shavings filled the oil well. I have already scrapped it. I have set out to swap the transmission from the red one, to the blue one, as well as any superior/newer parts.

Now to the questions:

1. Will the m5od from the red one (mated to the electric t-case) bolt right up to the manual t-case? If not, I assume I can swap the electric t-case with the buttons and 4wd computer...

2. Can I just swap the auto hubs from the red one (caps that come off when wheel is removed) onto the blue one with manual hubs? I want to do so because the autos seem to work fine on my red one and I would prefer to shift into 4hi "on the fly" - say when I come up on some ice or snow. Plus I will not be rock-crawling, just the occasional snow, mud, and sand.

3. After the trouble of removing the first transmission (on my back on a piece of plywood under the raised vehicle), I say to myself, "there must be a better way." Can I pull the engine and transmission as one unit out of the hood opening?

For the third question here are a few qualifiers... I am confident that I can handle removing an engine/trans combo as I have done it several times in other RWD vehicles. I would remove the radiator and anything else between the water pump and the front clip. What I don't know is if there is enough room in the engine compartment to get them out. Or if the radiator support can be removed within a reasonable amount of work. That would be ideal for me as I would not need to lift the assembly as high.

If I have to, I WILL do the swap from underneath, but it would really be nice to be able to remove both engines and swap the trans and replace the clutch and slave cylinder on the ground, and do a few other maintenance/prevention measures, then just slide the new and improved engine/trans assembly back into the blue ex.

I don't have access to a vehicle lift but I plan to rent an engine hoist.

I trust and appreciate your infinite cloud wisdom! When I do this, I will document with pictures and a write-up.

 

[LBarr2002]

Are you planning on using the engine from the red one or blue one? If using the blue one's engine, I would do the swap from underneath. It's a lot more work (hoses, wiring, accessories) to remove the motor just to swap transmissions and put it back in.

If you plan to use the engine and transmission from the red one, it would make more sense to pull them as an assembly.

I would plan to use the manual transfer case and hubs. The auto hubs can break in mud too, it doesn't have to be rock crawling. Many people look for the few factory manual transfer case manual hub explorers that were built.

 

[snoranger]

1) Yes, the manual case will just bolt on. No need to swap in the troublesome electric shift case.

2) I would use the manual hubs. They are stronger, last longer, and dont F'up on you when you need them. They are not a direct swap, you need to swap the nuts and washer to install the auto hubs.
(just lock them before you go out on a day you might need them.)

3) Did you pull the Y-pipe? The trans isnt hard to pull with the Y-pipe out, it can be done with it in the way, but its tricky. Pulling the motor to swap a trans is WAY more work then you need to do.

 

[EastoutWest]

interesting... Thank you for your replies!

No, I am using the blue engine; it runs really smoothly, is not rusted, has no leaks, and has fewer miles.

I thought there were potential problems locking the hubs and driving in 2wd... Or is the problem more if engaging 4wd without the hubs locked? Anyway, ya'll make good points and it sounds like it's not as simple as I thought it might be. I will keep the manual hubs.

I had to cut the y-pipe to get the old trans out. The bolts were rounding off and I even got a socket totally stuck on one. I have a sawzall now and will cut the bolts and replace after the swap. I can replace with the y-pipe from the red one.

My main issue is that I am working in a gravel driveway on a piece of plywood on my back. I'm not concerned with the annoyance of removing all wiring and hoses to remove the engine, that's easy to me, what I fear is trying to line up and mate the transmission from underneath... but I did just find out that I can rent a transmission jack from sunbelt.

For $#!^'s and giggles, let's just say I drop the trans of the red one from underneath, but I want to remove the engine from the blue one anyway... to paint the engine bay, engine, etc... It is already separated from the transmission, so removing it should be pretty simple. But what about removing the radiator support and sliding the engine/trans assembly down into the hood opening? Has anyone done that before?

 

[snoranger]

I have a sawzall now....


But what about removing the radiator support and sliding the engine/trans assembly down into the hood opening? Has anyone done that before?

Those 2 sentences will need to go together. They dont unbolt.

 

[EastoutWest]

oh... that's not what I wanted to hear.

Well, perhaps I won't try it then. I would need more than a standard engine hoist to be able to get the angles I would need to get the engine and transmission down in there i guess.

Thanks for your replies. I suppose the blue engine stays where it is then.

 

[92exp4x4]

The manual t-case should be sold to me if you want the project to work!

I never have tried pulling engine/trans together. You might be able to do it but its really long and unbalanced assembled. I just finished a similar project, auto to manual trans swap. Get all the fasteners undone, then remove the front wheels and set the truck on some wood blocks so its as close to the ground as you can get it. Then you will be able to lift the engine high enough to go over the rad support and roll it away.

When it all goes back together you can just shimmy underneath and have a friend move the engine while you guide it together to the trans, but i think its easier to install the engine then the trans from the bottom. I put a M5OD in by myself with no trans jack, its awkward but it can be done. (6'-0" and 155 lbs, I'm not that big of a guy)

Gravel sucks but if you put some plywood down you can roll a lift over it. Be careful and keep the weight as low as possible when moving. Get some helpers too.

Good luck, and that manual t-case is bad-a$$, those are really sought after. I passed on one at the junkyard about 10 years ago and have regreted it ever since. Never have seen another one in all that time.

 

[EastoutWest]

Good luck, and that manual t-case is bad-a$$, those are really sought after. I passed on one at the junkyard about 10 years ago and have regreted it ever since. Never have seen another one in all that time.

I knew it was rare but I didn't know it was that rare. I definitely want to use it. Besides, if I don't use it there will be a hole in the floorboard

Should be a pretty good driver when I'm done... I just hope the manual t-case out of the blue one (which had a blown transmission) works. It was full of clean fluid and turns and shifts freely by hand. Output shafts respond appropriately.

I appreciate the input and encouragement ya'll. I know it will be fine once I can afford the clutch, slave cylinder and other parts and actually get working on it.

Thanks

 

[snoranger]

I knew it was rare but I didn't know it was that rare. I definitely want to use it. Besides, if I don't use it there will be a hole in the floorboard

Should be a pretty good driver when I'm done... I just hope the manual t-case out of the blue one (which had a blown transmission) works. It was full of clean fluid and turns and shifts freely by hand. Output shafts respond appropriately.

I appreciate the input and encouragement ya'll. I know it will be fine once I can afford the clutch, slave cylinder and other parts and actually get working on it.

Thanks

No there wont be a hole, if you use the floor plate (12" x 18" plate the shifters go through that bolts to the floor.) from the E-shift truck. So you can sell it to 92exp.

Seriously, these T-cases are pretty reliable. Your manual case should be fine.

 

[EastoutWest]

Thank you, everyone, for your insight on this matter!

I have completed the swap. It was raining but I parked the two Ex's about 10 feet apart and strung some tarps up. It was a nice little tent and we stayed relatively dry. Did it from underneath with 1 helper, 2 bottle jacks, 2 floor jacks, and 3 sheets of plywood. Getting the trans down was hard, getting it up was easy. Funny, I would have expected the opposite. Unfortunately, I didn't want to risk ruining my camera in the rain so I don't have any photos for you.

Got the clutch and slave cylinder from Carquest. I used to work for them and love the company; and the parts are on-par with Napa. Since I used to be an employee, they gave me a break on the prices. Around $220 for the clutch kit, slave cylinder, 2 cans of degreaser, a bottle of lucas oil stabilizer, a can of carb cleaner, and some gasket material. I already had the ATF. Would have been around $280 for a walk-in. They had the parts in stock too! AA and AZ both did not, and I have learned that their employees can sometimes be clueless...

The clutch kit had a clutch line removal tool in it but I didn't realize that until AFTER I removed the transmission and installed the new slave cylinder. But the clutch line came out easily with a screwdriver.

We got the y-pipe off on the donor (Red) Ex but the bolts were completely seized on the recipient (Blue) Ex. I cut the pipes with an angle grinder. So its off to the local muffler shop with two sets of exhaust to combine. But first, I want to pump the gas out of the tank by removing the fuel line before the filter and running the fuel pump. Its been in there for probably more than 2 years.

At first, we fought with the transmission while holding it up on our backs for a while before I remembered to put the transmission in gear and turn the output shaft to align the input shaft with the flywheel. A helpful tip to remember!

Anyway, the rest was just plug and play.

*By the way, I've read a number of posts here that say that accessing the upper transmission to engine bolts is done from underneath the car, but I found it much easier to access those with a 13mm box-end wrench (or better, a gear wrench) through the passenger-side wheel-well (with the intake plenum and plastic liner removed). That direction presents the most access when the rear end of the transmission is raised. Of course that may be different when using a lift.

Anyway, thanks for the feedback and hopefully my little story helps someone else!

Also, is anyone near Charlotte looking for a fully functional 91 engine, electronic transfer case, or transmission extension housing? Or any other parts for that matter? Just not the transmission...

 

[tweakedlogic]

Congrats.

I always use a 3 foot long extension, wobble bit and socket with an impact for the tranny bolts.

Good job on getting it all together.

 

[zzzac]

How many miles does the engine have? How did it run?

 

[EastoutWest]

Either 160k or 260k. Probably 250. I don't know if it was ever rebuilt or what work had been done to it befoore I got it about 25k ago. It needed an oil change but ran great. I drove it every day.

There was an intermittent ticking which would come and go at idle. Otherwise, it didn't burn any oil, no smoke of any color, and seemed to have plenty of power and life left. I would hate too scrap it...

 

[EastoutWest]

Thanks tweakedlogic, I'm happy to have a vehicle that I have some pride in again. The old one was so beat up it was sometimes embarrasing. And now I know this one from top to bottom AND have a working fuel gauge!

My only regret is cutting an exhaust bolt that I ended up paying the exhaust shop $125 to remove