"ultimate" h55f 5spd conversion combo

[woytovich]

Thanks for the info...

I am installing an H55/split TC without a TC mounted parking brake (I sourced a later model FJ40 rear axle with OEM PB!). Do you think I'll still need to mod the X member? How about with a 1 or 2" body lift?

Oh... and this is with an aluminum tub....

Mark

 

[FJ40Jim]

Mark, it depends on the frame. sometime aroun 79-80, the frame was modded to accept the longer H55 tranny. IIRC, I put a H55 into a ~1980 FJ40 a few years ago without moving the X-member. It was not an 81-newer FJ40 because we had to swap in a split case and do a RDB swap to the sucktacular GM p-brake rear calipers to make it all work.

 

[woytovich]

It's a 78 frame.

Any pictures of the mods necessary? Relocate the entire X member or mod the existing one?

 

[orangefj45]

RDB swap to the sucktacular GM p-brake rear calipers to make it all work.

truer words have never been spoken.

 

[orangefj45]

the body lift will help with the trans tunnel mods as the h55f top cover is taller than the fj4x series h41 and h42.
if you run the parking brake, then you definetly have to remove the x-member. you might be able to get away with it in the stock location if you're omitting the drum on the back of the tc. but it's going to be harder to get the trans and t-case combo in there with the x-member in it's original location.
having the later rear axle in the rig is a great mod. the ebarke works great and it's a bolt-in. excellent choice imho.

 

[woytovich]

the body lift will help with the trans tunnel ...you might be able to get away with it in the stock location if you're omitting the drum on the back of the tc....
having the later rear axle in the rig is a great mod. the ebarke works great and it's a bolt-in. excellent choice imho.

Thanks for the info. I'd like to avoid moving the X member if I can. I got lucky with the PB rear axle... it was for sale locally at a great price, I was all ready to do the RDB w/PB conversion...

I sourced a floor mount PB (including a floor cut) from an FJ60 to bolt into the floor of the aluminum tub...I won't know how that'll work until I get the tranny/TC in place though. Other than a custom cable length it should work out ok.

Mark

 

[hicruise55]

Looks very awsome! but wouldn't the ultimate have the crawler gears in the splitcase? I have been thinking about swaping them into my FJ55... is there any drawbacks? I figured you would be the man to ask?

 

[PabloCruise]

hey mark.
thanks for the reply. you do have to remove the x-member behind the t-case in order to get this combo into an fj40. i recommend moving it back closer to the rear spring hangers. i aalso like to weld a scab plate to the inside of the frame rails to strengthen the entire assembly/structure.
i do not have any pics of this particular combo installed in the truck and i will not be doing the install myself; the customer had me build it. the entire setup will be shipped to ipor on the easy coast where the install will take place.
hopefully lance and the crew will get a chance to take pics of the install and post them up here on mud. otherwise i'm sure the owner will, he's a mudder as well.
however, i finished a very similar conversion here at the shop a couple of months ago. i'm afraid i do not have any pics of the installed combo without the skid plate installed. here are a couple of pics of the completed job. this 40 has a body lift so it only required minimal tunnel mods.

georg @ valley hybrids

Is that a custom cross-member for the back of the H55F? Any additional pictures of that?

 

[orangefj45]

Thanks for the info. I'd like to avoid moving the X member if I can. I got lucky with the PB rear axle... it was for sale locally at a great price, I was all ready to do the RDB w/PB conversion...

I sourced a floor mount PB (including a floor cut) from an FJ60 to bolt into the floor of the aluminum tub...I won't know how that'll work until I get the tranny/TC in place though. Other than a custom cable length it should work out ok.

Mark

i guess there's only one way to find out if it's going to work or not. start with the tape measure and go from there.

i have used the fj60 rear axle with the complete ebrake setup in 40s before. you can re-use the existing cable but it has to be modified slightly.

make sure to post a thread with your swap when it happens. should be good info for lots of fellow mudders.

 

[orangefj45]

Is that a custom cross-member for the back of the H55F? Any additional pictures of that?

the x-member in the pics is a modified fj60 x-member; the later style. we shortened it and made new frame brackets out of angle iron. worked out really well. not as sano as some of the custom units we've done but we were on a budget and had the original x-member on hand.

 

[orangefj45]

Looks very awsome! but wouldn't the ultimate have the crawler gears in the splitcase? I have been thinking about swaping them into my FJ55... is there any drawbacks? I figured you would be the man to ask?

good question.
i'm not a big fan of the mark's gears. not at all actually. they cost $2k,the gearing is not that much lower, they run extremely hot and noisy. so much so that a few people have taken them back out. so i won't install them in a customers' rig to avoid disapointment.
but to each his own.


the "ultimate" would be a 4:1 gear set for the split case and there's a little talk about it but nothing concrete. so we'll leave that alone for now.

georg

 

[Blue77FJ40]

Georg, how doable in a '40 is it to add in a toybox to this mixture? H55f/toybox/splitcase/pbrake.

Thanks, Dan

 

[woytovich]

Georg, how doable in a '40 is it to add in a toybox to this mixture? H55f/toybox/splitcase/pbrake.

Thanks, Dan

And even without the PB...?

I imagine it's then time to move the rear axle backward?

 

[Poser]

the "ultimate" would be a 4:1 gear set for the split case and there's a little talk about it but nothing concrete. so we'll leave that alone for now.

Having installed the 3:1 low range set in a split case, unless you are going to make a new gearbox, there is not room for a 4:1 low range gear inside the OEM split case.

 

[orangefj45]

Thanks for the info. I'd like to avoid moving the X member if I can.
Mark

not gonna happen. i did some measuring at the shop today using a 77 fj40 for dimensions.

there's roughly 22.5" between the back of the bell housing and the front of the trans x-member.
the h55f/split case combo is almost 22" long where it counts.........

so plan on doing some mild frame mods.

 

[orangefj45]

Having installed the 3:1 low range set in a split case, unless you are going to make a new gearbox, there is not room for a 4:1 low range gear inside the OEM split case.

yup, it's one of the major hurdles to clear.......

 

[PabloCruise]

the x-member in the pics is a modified fj60 x-member; the later style. we shortened it and made new frame brackets out of angle iron. worked out really well. not as sano as some of the custom units we've done but we were on a budget and had the original x-member on hand.

Muchas Gracias - that is some great info - I appreciate it!

 

[orangefj45]

anytime!

georg

 

[orangefj45]

Georg, how doable in a '40 is it to add in a toybox to this mixture? H55f/toybox/splitcase/pbrake.

Thanks, Dan

sorry i overlooked this post earlier.

you're going to run into a few obstacles:

1) no toyboxes available right now and none anytime soon. not for an h55f anyways.......

2) overall geartrain length will be a major issue. you will have to move the trans x-member back for sure. you're also going to run inot some rear driveline issues. chances are you'll have to move the rear axle back.

3) body clearance. that combo is super long and will require modification of the trans tunnel and tub at the rear of the tunnel. the t-case will hit the bottom of the tub so you'll have to raise the floor back there.

i guess those are the main issues i forsee right off the bat. it all depends on which engine you're running and how the suspension is set up as well.

hth

georg @ valley hybrids

 

[Blue77FJ40]

Thanks for the feedback, Georg. I'm aware of the toybox situation and the x-member, so that's not news, I knew about the strong possibility of flipping the rear springs, but was unaware of the need to modify the tub. I have an uninstalled 1" bodylift kit, that would only help marginally. I suspected that the rear driveshaft might be very short, even w/cardan joint. Looks like I'll be sticking with a 4spd tranny, although it would be sweet to have that fifth and to match the shifting on my Taco!