Transmission Swap or Differential Swap: Two hurting 3rd Gen T4R

[SteelRunner]

Hello gang,

Here is my dilemma. My family owns too many 4runners and theyre getting older.

My fathers '96 limited just had a pink milkshake with 330,000 km on the clock and he has decided not to fix it as he desires a newer, more reliable vehicle.

I also own a '97 sr5 with manual trans and a diff lock at 315,000 km and gaining. I bought it because of the unique combination of options. I have since had a frame repair but I do drive the truck. It is plated for the road however the rust is catching up.

Of greatest concern, the rear axle on the '97 is weeping fluid through the cover on the top and through the housing from severe rust.

I am not currently aware of the condition of the frame on the '96 but i assume its better than my '97 and considering this, should I consider putting my 5 speed manual in the '96 limited? Or should i put the '96 limited front and rear diffs on the '97 and hope the frame outlives the rest?

I'm pretty handy with most repairs but have not swapped a transmission. The diffs I think I could tackle if its just bolt in.

What should I do or should I just look for a different vehicle altogether? I do not have a great deal of time for this project, if any.

 

[the great him]

well swapping diffs is not gonna help if the axle housing is leaking. you will need to swap the entire rear axle. personally i think the axle swap would be easier, as the transmission in the limiteds are auto and are electronically controlled. you would run into a lof of other hassle by trying to make the trans swap work. that being said the front diff is a PITA to remove and requires the steering rack to be loosened and slid back a little. swapping transmissions would be physically easier, but not practical do the the electronic controls and other hassles, such as setting up the shifting linkages, plumbing the clutch pedal ect.

while you have the axle out as well as front diff, you might want to think about cleaning them up really well, scrapping any rust off and painting them with a good primer sealer and then covering that with a few good layers of epoxy paint. not only doing the axles but also the entire underside of the runner, especially up in the wheel wells and around the frame. -make sure to clean everything very well before paining.

 

[Chill will]

If you can weld or get someone to weld for you I have a $60 fix. I had the same issue as you the weeping axle housing. I used JB Weld as a bandaid for nearly 2years. Well I found Barnes 4wd and they make heave duty diff cove to replace the ones on a toyota. They are heavy duty so you won't even need any additional diff protection. It is an exact fit didn't even need to be trimmed .

https://www.barnes4wd.com/mobile/Toyota-Pick-Up-Heavy-Duty-Differential-Cover_p_228.html

 

[packweco]

I wouldn't do either. Sounds like you'll lose the diff lock if you swap axles, and putting a manual in an auto truck would be quite a project. Look around for a diff lock axle housing with less rust than yours, spend the $300, and bolt 'er in.

 

[Chill will]

I say go with the diff cover from Barnes 4wd it's a direct fit, heavy duty, and affordable. I think this would be your cheapest option.

 

[JBurt]

One more thing to mention if you swap tranny's. Once you put the manual in the limited you'll have a check engine light on because the ecu won't be getting a signal from the shift solenoids. Doesn't effect performance, but the light will always be on so you won't know if you throw a new code and it might impact any safety inspections.

You can get the light to go off if you swap in your manual ecu. But to do that you either have to swap wiring harnesses or repin all your wires to fit the manual ecu.

Do you have pics of the rust on the 97 frame? It sounds like welding on the axle cover seems like the easiest and best option.

 

[JBurt]

One more thing to mention if you swap tranny's. Once you put the manual in the limited you'll have a check engine light on because the ecu won't be getting a signal from the shift solenoids. Doesn't effect performance, but the light will always be on so you won't know if you throw a new code and it might impact any safety inspections.

You can get the light to go off if you swap in your manual ecu. But to do that you either have to swap wiring harnesses or repin all your wires to fit the manual ecu.

Do you have pics of the rust on the 97 frame? It sounds like welding on the axle cover seems like the easiest and best option.

 

[SteelRunner]

Terminology

Excuse my terminology, I was referring to swapping the whole axle in the rear. I would still have the diff lock as both trucks in question have one.

It does seem that the Barnes cover is the easiest option. You had it installed without removing the axle?

My ebrake cable also snapped yesterday I'm assuming from rust as I have not had a chance to inspect, just to throw another wrench in my gears.

I'm going to post some pics of the frame rust and axle on my 97 and see what the opinions are on how long it'll hold up.

Sad to say it but I'm considering moving away from Toyota because of all the rust issues up here in Canada.

Thanks for the replies

 

[SteelRunner]

pics

heres a pic of the frame rust thats present


heres a pic of the rear axle rust. you can see where its already been sealed


i can see now that the diff cover can be installed with the axle in the vehicle but it appears from the pic that the gears were removed. anyone care to provide an estimate that a shop would charge to install one of these diff covers and weld the other problem areas?

 

[JBurt]

It looks like your axle housing is leaking to the right of the housing on that last pic.

 

[SteelRunner]

its leaking on the drivers side axle tube and the diff cover that i could see

 

[zgensler31]

Speaking from experience....

That trans swap is not as difficult as everyone makes it out to be.

And you are in the best situation to make it happen if you choose. You have a donor vehicle with every part you need.

Swap the parts over....
Look up your year specific wiring diagrams.
Run wires from trans plug to the cab.
Enjoy the ultimately rare limited 5 speed.

Yes you'll have to live with a cel. Which isn't that bad.
Yes you can make it a lot more difficult if you choose.

Only hitch is the transfer case. Limited is elec. Manual Is manual. You either get to tap a couple more wires, simple and what I did. Or fab up a shifter handle to get the elec case shifter out of the way of the 5 speed.

But seriously. I've got a thread, and Dan the man has a thread and there's a few others about the 5 speed swap. if your seriously considering it. Read them and see how easy it is.

 

[poleclimber63]

Too bad about the rust. I know Eastern Canada is really hard on vehicles... From the pic it looked like the housing was leaking too... I would say swap the rear ends (check gear ratios, as I have no idea if they're the same auto/manual -- probably the same...)

OR

If your Dads' 4r is in MUCH better shape, swap out the tranny. You'll even have a spare engine! If its just a little better (rush on the frame etc.), it may not be worth it. For me to go to that much trouble, it would have to be in alot better condition! You'll learn a ton! I did an engine swap this Spring and decided to do it because the body and frame is showroom, and the vehicle had relatively low KM's. I communicated with a member here that did an engine AND tranny 5spd/auto swap at the same time!

Here's his thread: http://www.toyota-4runner.org/3rd-gen-t4rs/155303-possible-5-speed-swap-input-appreciated.html

another source:
http://www.toyota-4runner.org/3rd-gen-t4rs/160354-auto-5-speed-swap-need-your-input.html

You have the pedal hardware etc. from yours, and I'd swap the ECM and harness. Of course some research is in order. You need to know what differences there are between 96-97's to ensure this ECM is completely compatible with the 96 engine (ie. mine wasn't, as the fuel injectors were different). Do your homework. As mentioned above, the auto has a different harness. Another member that's done a swap, and is very knowledgeable is:
http://www.toyota-4runner.org/3rd-gen-t4rs/61636-cobs-4runner-timeline-pic-heavy.html
Good luck!