The first 2nd gen 2wd to 4wd IFS conversion

OK Guys.

Just click on the link. Ray's 2wd to 4wd build

I was just too lazy to put it on this board as well. I'll do it later but for those of you who can't wait just click on the link and get the full story.

Wyatt

 

Subbed

 

OK. Lets get started. First, as many of you know, the prerunner and the 4wd version of the 2nd gen Tacoma uses the automatic a750F or A750E transmission behind the 4.0 motor. The difference between the two are the rear extension housings. This one is for the 2wd version and has no way to accommodate a transfer case.




You can see that at the rear it gets really small for the drive shaft.

This is the rear of the 4wd version of the A750F trasmission with the marlin coupler and seal adapter installed. The t case bolts to this without the Marlin seal adapter and coupler when your not using a crawl box.


Internally the transmissions are the same. It's just the rear output shaft and extension housings that are not the same. They also use very different transmission mounts and cross members between the two.

But thats not the fun part though. We noticed that there is also a difference between the frames of the prerunner and the 4wd versions. The crossmember mounts on the frame are an inch forward on the 4wd version compaired to the prerunner. That caused us the have to make a custom cross member.

But I'm getting ahead of myself.

First we had to gather all the parts. Transmission, t case, crawler box, front drive assembly with hubs, drive shafts, front diff and ADD system, front and rear drive shafts, RST ADD system kit, twin sticks, and all the fluids.

First we took off the front skid plates and then out came the transmission.



Then while we were flushing the new transmission we went to the front of the truck to start installing the front drive system.

First we removed the wheels to get at the hubs. On the 2wd version there is a just a dust shield that needs to be removed on the spindle.


You have to remove the 2wd hubs so that you can install the 4wd hubs.




We knocked out the dust shield so that we could install the front cv axle shafts.





Then you install the front 4wd hubs so that you can install the front diff assembly and the front cv axle shafts. We used all new factory Toyota bolts for this.



Then it was time to put the front diff assembly in.



Front diff installed.



In this picture you can see the ADD actuator.


Then the cv axle shafts go in.





The front diff assembly in it's new happy home.




But now the trick is to get this ADD system to work without a computer. So with the previous help of Kevin from ATO I created a system kit that allows you to activate the front ADD system on this prerunner without a computer.

This little kit allows you to use a switch to engage the ADD and to disengage the ADD on the front diff.



Once that is installed you can install the switch that activates the ADD. We decided to put it in one of the blanks on the left of the steering wheel.




When you turn the switch on and the ADD engages, the light will come on to let you know it's engaged and then you hit the switch again to turn it off and the lights goes out to let you know it's now disengaged.

With the front done it was time to do the transmission, crawler, and t case.

First the transmission was installed.


Then when it was time to install the crawler we had to cut the cross over pipe for the exaust.


Because the transmission cross member on the prerunner is an inch further back than the 4wd version is we had to make a custom cross member. We took the 4wd cross member cut the ends and the center section off so we could use them again. We then took some 1inch by 3 inch square tubing and made our custom crossmember.


We inset the center section and channeled it to drop the t case down an inch.






Then it was time to install the crawler box and the t case.






With those installed it was time to move to the interior.
Out comes the pretty stuff.


So that we could find out where these sticks are going to go.


Cut some holes and see just how long we need to make the crawler shifter.


Then make a hole for the twin sticks for the t case, seal it and put everything back together again.



Once we did that we set our focus on the drive shafts. because we had a crawler, it meant making the front drive shaft longer and the rear drive shaft shorter because the crawler box moves the t case back 8.5". This is where we ran into another difference between the frames of the 4wd and the prerunner. The cross member for the carrier bearing for the rear drive shaft is back 2.5" more on the 4wd version than it is on the prerunner which meant we had to modify both sections of the rear drive shaft. Which means the front section of the drive shaft has to be shortened by 10.5" and the rear portion has to be lengthened 2.5" You cannot use the prerunner driveshaft as it does not have a flange section of the front of it.
Here you can see that when you place the drive shafts so that they will bolt to the rear axle the carrier bearing is now in a different spot between the two.


Another issue we ran into was the fact that the prerunner and 4wd trucks use different size rear axle flanges so that needs to be addressed as well.

Once that was all done we took it for a test drive and all was well. No leaks, the ADD works as planned, And the t case and crawler work like they should. Best of all there are no leaks and it's very quite.


Love it.

We then took it out on the TTORA Big Bear run. This was one hell-of-a-test. It rained all day and the trails were a complete mess but the truck did better than expected. When had to winch in one very bad area but other than that it was flawless. Here we decide to see just how high centered we could get it. LOL Had a good time.


This is the only picture we were able to take because the weather was so bad. Here is a video I took from inside the truck at the gate keeper of John Bull trail. Even in all that rain he made it up the trail.



Keep an eye on this rig as we have more plans for this sweet rig.

 

Whats a ball park on how much it cost. Minus the crawler box.

 

X2 ...want 4wd but no crawler box

 

Wyatt, does the front diff just bolt right up?

And I would guess w/o crawler, I bet you $5,000

 

Yes, the front diff just bolts right in.

 

I'm not exactly sure what Ray payed for the parts he gathered but yes, it is around that amount $5,000 to $6,000 but each is different. Ray had a ton of stuff done to his truck that we did besides the simple swap. But in the end it was worth it to him. He loves the capability it has now and is just surprised at what it can do.

 

Sweet. Nice work as always.

 

what if you just used a 1 piece rear shaft? seems like that would be easier

 

We actually did use one of my extra one piece drive shafts but with 33" tires it is a little easier to get into the rocks than the two piece is. He is going to larger tires soon which will probably require him to use a one price drive shaft.

 

Thanks man. Hope all is going well with you.

 

These Tacoma's are notorious for have drive shaft wobble after you modify them and this one was no different. The two piece drive shaft and the super soft carrier bearing are just not a good combination for a modified truck.

I had this wobble when I did my truck and the solution was a one piece drive shaft so thats what we did for Ray. I got a front drive shaft from a third gen 4Runner, took it to my driveline guy and he built up a nice one piece drive shaft that took all the wobble and vibrations out of Rays truck.



We also put in a triple drilled rear diff flange as well as a triple drilled rear flange at the T case. this way if need be he can use another drive shaft to get back home should his take a dump.









Ray has a super clean IFS truck now and is just waiting ti hit the trails again.

 

wow! this is awesome! great work!

 

Thank you very much. Ray is really happy with his build.

 

Tell me more about who did the flares wyatt! Please!

I'm just curious. Clearly mine are done as well but just wondering how they did his and who did it.

 

Ray actually did them him self. I think they came out really good. I'll try to get a little build thread on it when I see him again. It may be this weekend. Gonna do a little work on the rigs and then take them and play a bit.

 

Okay, cool. They do look good.

Thanks for the info! Nice work.

 

ughh i want 4wd soooo bad!

 

Does ATO sell the 4wd wiring kit?