Cadin

Hello All,

I have a R151f out of a 1987 pickup that when I removed the transfer case shifter the 4wd shift rail was sheared where the tranny and transfer mate.

I will be tearing into this box soon, and in the meanwhile I would like to keep the truck mobile. Will the chain driven xfercase behind the R150 mate to the R151f?

Does anyone has a clue on this?

Thank you Big Time!

jtinco

No, your inputs are different. That is why companies sell adapter plates to go behind the R150f transmission to run the gear driven (21 or 23 spline input) tcase like the R151f.

Cadin

Right on, Thankee.

I can convert a 21-spline RF1A to 23-spline via Marlin's gear and toss that in correct?

Then I can rebuild the other and maybe run dual 23 spline cases someday in the sunset?

Cadin

Alternatively, could I also bolt up the v6 5-speed tranny and transfer?

(are they (the R150/RF1A) combined the same length as the turbo setup (R151/RF1a)?

((So I can rebuild it on the bench and still use the rig.))

Cyberman

Couple of options here. You can just buy replacement shift rails and just fix your transfer. Or, get a 23 spline input gear for another front shift transfer and put it in. Or get a 23 spline 4.7 gear set.

I think you can change the bell housings between the two trannies, bit the shifters might not line up exactly in the floor.

Cadin

Right on, Thanks!

I had even thought about using the top-shift for a future double xfer application. For now I have sourced a local V6 tranny and xfer, I plan on swapping them out so I have the truck mobile and enough bench time to rebuild the tranny/xfer since I have it/them out.

The syncros are a bit sloppy, and it would be nice to upgrade the shift fork, and perhaps some different gearing.

aztoyman

The chain drive transfer case will not bolt up to the tail housing of the R151F.


The R151F and the R150F basically have interchangeable guts. The center section between the bell housing and the tail housing are interchangeable. Different 1st and 2nd gear ratios is only difference.


You can put a R151F bell housing on a R150F and bolt it to a 22RE but the R150F tail housing fits a chain drive case.


You can also put the tail housing and shifter parts from a R151F onto a R150F so it WILL bolt up to a 23 spline gear drive case.


R151F's are usually forward shift but you can cover the opening and still use a top shift case.


You can make a 21 spline T-case a 23 spline just by switching the input shaft. Direct swap.


This applies to early R150F for 3.0 V6. Later R150F for 3.4 V6 has longer trans input shaft, deeper bell housing and slave/clutch fork on driver side. Plus different T-case bolt pattern.


Your shifter location will change if you do any of this. I built a hybrid trans and dual case setup and have pics if you need them.

Cadin

Hey Aztoyman, I would certainly like to see those pics if you could! (Thankee!)

That is good to know about the tail housing, I was just going to grab the entire v6 tran-> case locally for a song since I have to dig into the tranny (The shift rail sheared), and rebuild the tranny and transfer on the bench.

Perhaps some XD 4.70:1 gear sets are in order...


I was thinking about the input shaft swap with a 21 spline to run duals.

What do folks think about the Marlin XD 4.70:1 gear set vs. dual cases?

Thank you Super Big Time for the info about the 3.0 vs the 3.4 though; I'm not sure which the donor rig is. It would be sad to be lifting it in and realize...

dropzone

iTrader: (6)

I would do duals vs a single 4.7 case. I have a 2.28 front crawl box and 4.7 gears in the rear case. 4.7 low range is too low in between obstacles IMO.. the one advantage to a single case with 4.7's is no driveshaft work is necessary.

scuba

Right but, if you were on a budget, a single 4.7 case is better than not having a crawl box. When funds allow later, that's when you can throw in another case.

phildelfino

if you have an r151 from a turbo truck, it's already 23 spline. you can change the bellhousing and run it, after repairing the shift rail.

marlin does not offer an adapter to double up the cases you have (as far as I know). the r150 is a chain drive case.

you may need to do something to your existing driveshaft, but a competent shop can fix hat for you in a day usually.

aztoyman

dropzone and scuba both nailed it so think about your budget and what you want to do in the long run.


I first ran a single 4.7 case. It's WAY better than stock for the hard stuff. BUT.......there were plenty of times when I wished I had stock gears. So if I had to do it again, I would run duals.


Marlin's gear sets are premium quality. I am always on a tight budget and got a set of TG 4.7's for a smoking deal. Haven't had any problems with them. Don't want to start a brand war so get whatever you want.


If you already are running the R151F I personally would just keep running it and fix your T-case shift fork. Moving your shifter location is a pain and so is dealing with adapters.


If your trans is that sloppy swap in the guts from the R150. I actually like the gear ratios better than the super low 151 set. They were fine off road but annoying on the street.


Headed to work. I can post pics later.

aztoyman

OK,Here's some pics showing a 21 spline and 23 spline T-case input gear side by side. Other than the spline count/diameter at the end of the shaft, they are totally interchangeable. Even the bearing and snap ring are the same.


Somebody on another forum told me I was full of it so I took pics.




Here is both gears going on the same case.






You can swap shift rails too. You can easily use top shift or forward shift rails in your case.


I even ran one of each to make a twin stick setup using all stock Toyota parts when I had a single case. I have pics of that too.

aztoyman

Here's what you swap out as far as guts to the trans. Direct swap (3.0 V6 only).






Actually all you have to change is the bell housing and tail housing including the tail housing shifter parts on to the V6 center section. You will have a fresher trans and better gear ratios for the street IMHO.


Stick in Marlin's shifter socket and/or his quick shifter and you will be a happy camper.

aztoyman

Stock, I originally had a W56-B and single top shift case with my 22RE. Then I went to the R151F which is forward shift and single case with 4.7's and my home brew Toyota Twin Stick.


Here's the two side by side.






Now I have a 3.4 so I had to stick the 3.0 V6 bell housing on, stock 23 spline front case, 23 spline 4.7 rear case, Marlin quick shifter and Davez Triple Shifters.


Going from top shift to forward shift puts the shifter several inches forward and with the 3.4 even farther forward. Lots of floor and shifter mods to get this done.

aztoyman

Here's my Toyota Twin Stick using one forward shift rail and one top shift rail. Modified and combined two stock shift boots and retainer plates. Easy to do if you decide to run a single case.

Cadin

Thank you for the awesomely clear pics; Sweet idea on the single rail dual shifters! Nice job fabbing that tunnel as well.

Here is a pic of that rail:



I still have a couple of questions; but first to put my situation in context...

My setup is a Fj80 application, with the r151f and a mercedes turbo diesel pushing the ordeal. This was very much a "massage to fit" project, and as such access to the bellhousing without pulling the motor is tricky (I'm not sure if it is possible!). Here is the "massage-to-fit" in the floor for the clutch release lever travel...



Can you pull the tranny by letting the forward case of the tranny and bellhousing remain attached to the motor? (I know I would have to be mega-careful in exposing the "forward guts" upon removal. Or is there a retaining clip or similar on the input shaft to the clutch preventing removal?

I certainly like the idea of dual cases, but since I am running an offset Fj80 diff with a centered rear driveline output, I think I have used all the range of the driveline without going to double cardan for the rear. I think I may have to wait on duals until later; the 4.70:1 gears are an attractive option, so it is nice to hear folks' honest experiences for and against. I certainly hardly use 1st unless I am stopped or in the field.

It is good to know that the R150 is well behaved on the street, the low 1st on the R151f doesn't bother me nearly as much as the 3rd-4th jump with the turbo diesel. They feel light years apart, and I am either revving 3rd or lugging/bogging/overloading 4th.

Cadin

Room is a little tight...

aztoyman

Wow, that does look tight for access. Sorry, the trans has to come out to take it apart.


If you look at the pic with the trans apart you see the front retainer plate. It has to come off to access the snap rings on the bearings in order for the case to pull off.


The trans doesn't have to come out to fix your T-case shift lever though. It just sticks out from the T-case and into the housing of the trans. Sorry if you already know that.


You should be able to find one. Maybe even fix the one you have.

I really didn't like the gear ratios of the R151F on the street. It is intended for the turbo lag of the 22RET. I'm very happy with the ratio of the R150F and it's actually fine off road too.

Cadin

That's what I thought; no worries, if it comes to it I can hole-saw the firewall and buy proper rubber plugs the right size. (Better to know now!)

I did know about the shift rail, but Thank You for mentioning it!

Since I can get a 3.0 tranny/chain xfer for the same price as a used gear drive xfer + 23-spline input (not including labor/time to swap), my current plan of attack is to pull current set up; use the forward casing/bellhousing with the R150/Chain while I replace the shift rail and inspect the R151f and rebuild gear xfer if needed. I will wait on rebuilding the R151f until I see how I like the R150's pattern for this rig.

I have a rail on order from Toyota (ordered a while ago) , though with your double shifter idea, maybe I should have gotten the rear shift rail!