Can I make an h42 into an h41?

[Bryan062087]

Can I make an h42 into an h41 by swapping the lower 1st gear in and leaving everything else?

I think the gear ratio's (2nd-4th) of the two transmissions are slightly different, not sure how this would effect the real world driving experience.

But would this be do-able or am I out of my mind?

Was thinking I could just buy the first gear from toyota?

 

[Stumpalama]

No. You'll need to swap all the guts from an H41 into your H42 box, minus the reverse gear I believe. I have an H41 in an H42 case in my FJ40 and I like it alot!

 

[Butt Ugly Chuck]

PM cruiser_guy. He was talking at one point about bringing H41 gearsets up from Central America.
Butt

 

[Bryan062087]

Darn. I knew it seemed too easy.

What all is different between the two transmissions? You are saying the only thing interchangeable is the reverse gear?

 

[Stumpalama]

I'm talking about the little gear that is shifted when the tranny is put into reverse... I don't think there is a need to change that one out as they have the same ratio.

 

[cruiser_guy]

Darn. I knew it seemed too easy.

What all is different between the two transmissions? You are saying the only thing interchangeable is the reverse gear?

Every gear goes through the counter shaft at the bottom of the tranny. If even one gear is different that counter shaft is different. In the case of the H41 vs. H42 they are all different with the exception of 4th which is still 1:1 (couples the input and output shafts).

I have an H41 gear set here that I can bring north if you want. It has everything needed to convert but it's for a "B/3B" diesel engine.

 

[Stumpalama]

I have an H41 gear set here that I can bring north if you want. It has everything needed to convert but it's for a "B/3B" diesel engine.

Meaning you'll need a new input shaft because B/3B shafts are different from F/2F/H shafts. The B/3B input will not mate up to an F series engine.

 

[cruiser_guy]

Meaning you'll need a new input shaft because B/3B shafts are different from F/2F/H shafts. The B/3B input will not mate up to an F series engine.

Exactly, unless of course you have the "B/3B" diesel

I'm on the hunt for the "F/H" shaft but I haven't found it yet.

 

[Bryan062087]

Well, I think I've found a complete h41. Thanks for the information.

 

[Stumpalama]

Now, remember, your transmission crossmember mount is different from a 40's. The mounting point on the FJ62 transmission crossmember is flat. I don't know if the transmission isolator from an FJ62 bolts to an H4X tranny, altough, I can't see why it wouldn't.
Also, the output shaft (into the transfercase) of the H42 and H41 can have either 16 or 19 splines. Your transfer case on the 62 is a 19 spline split-case. So if you are intending install the H41, I'd make sure it is a 19 spline output. But if it isn't, buy an ORION T-case and get 4:1 If your going this far, why not an H55F transmission? The difference in the 1st gear is small 4.95 for the H41 and 4.85 for the H55F. Plus you get OD with the 5 speed.

Good luck!
-Stump

 

[Bryan062087]

That is very helpful about the spline count. Thanks.

And I'm not doing the h55f because I can't afford it!! Although I'm sure it would be nice. Hopefully I will like the h41 and my highway rpms won't be too bad with the 3.7's

Please see the other thread I started about actually doing the conversion.
https://forum.ih8mud.com/60-series-...-conversion-gear-swap-have-few-questions.html

 

[Slowerthanu]

That is very helpful about the spline count. Thanks.

And I'm not doing the h55f because I can't afford it!! Although I'm sure it would be nice. Hopefully I will like the h41 and my highway rpms won't be too bad with the 3.7's

Please see the other thread I started about actually doing the conversion.
https://forum.ih8mud.com/60-series-...-conversion-gear-swap-have-few-questions.html

Unless you changed your 3rd members on your 62, you have 4.11's. Toyota switched back when they added the slush box.

Nevermind, I read your other thread. Why are you downgrading to higher gearing?