FJ40 Transmission Hump Identification? (Image)

[Ackcruisers]

I’m preparing for a 4 speed and hoping no modification is required to transmission hump other than expanding shifting hole. Can someone identify this hump? It’s on a 1976 Colombian truck with 3-speed. This was a stock option for these SA trucks in 1976.

 

[brian]

It's actually the rear of them, where it fades back to the tub, that requires the mod.

 

[Living in the Past]

You should be fine other than the shifter opening. To be sure look at the back. If it has a straight edge across the back that ends at a channel in the floor you have the US pre 9/72 style. But I think you will find you the flange this is running down the sides will continue around the back. Betting the cover you have is the same as our 73 and early 74 that still had a three speed. Only difference is you also have the two cowl vent drain holes. Up to 75 the drains ran thru the firewall. The 9/72 floor/tunnel cover was for markets like Australia that got a four speed in the 73 model. Once I start working on my 73 plan is to just switch a 78 tunnel cover to install a four speed.

 

[Ackcruisers]

It's actually the rear of them, where it fades back to the tub, that requires the mod.

Here are some other pictures.

 

[ToyotaMatt]

I’m preparing for a 4 speed and hoping no modification is required to transmission hump other than expanding shifting hole. Can someone identify this hump? It’s on a 1976 Colombian truck with 3-speed. This was a stock option for these SA trucks in 1976.
View attachment 2406035

Paul ,

you have a 1976 Global Spec. Body tub , however its for a 2F and optional H41 4Speed trans , you WILL have to completely weld up both

the trans and t-case shifter stick holes and relocate them , but the cover itself minus the 2 shifter holes should be the same H41 vs J30

trans options from : 9/72-12/78

i know others will chime in with more solid tech, this is all i know

 

[Living in the Past]

Think your transfer case opening should be fine. It bigger than the one on my 73 and shaped like the four speed. While I was waiting for a four speed cover I had to modify my 68 cover for the four speed shift tower. It did line up but wasn't in a completely different spot. I trimmed the back of four speed tunnel cover to use on my 68 because the 9/72-12/78 are taller for the four speed which is taller than the three speed. Toyota made all the covers taller 9/72+.

 

[brian]

Probably easier to source a new hump.

 

[Ackcruisers]

Probably easier to source a new hump.

If I source a new hump, I doubt the bolt holes will match across firewall. With all the modifications needed to do this i.e Bell housing, drive shafts, tcase and now Transmission hump, I might be better off just to go for the 5 speed.

 

[Living in the Past]

Probably easier to source a new hump.

Not sure how easy that would be to find a clean rust free hump. Plus would be pretty expensive. I live in the Southwest and acquired a few years ago. Much easier and cheaper than.

If I source a new hump, I doubt the bolt holes will match across firewall. With all the modifications needed to do this i.e Bell housing, drive shafts, tcase and now Transmission hump, I might be better off just to go for the 5 speed.

Not sure what modifications your talking about. Your current hump should be made to clear a four speed. Personally think you would be wasting money to do anything ahead making before you know you will really need it. People install a four speed into pre 9/72 40 series using the old hump all the time. Did it on my 68 when the hump I bought didn't arrive until after I needed the cruiser on the road. I know the H55F is taller than the H41/H42. That would require modifying the transmission hump and possible the floor.

 

[Ackcruisers]

Not sure how easy that would be to find a clean rust free hump. Plus would be pretty expensive. I live in the Southwest and acquired a few years ago. Much easier and cheaper than.




Not sure what modifications your talking about. Your current hump should be made to clear a four speed. Personally think you would be wasting money to do anything ahead making before you know you will really need it. People install a four speed into pre 9/72 40 series using the old hump all the time. Did it on my 68 when the hump I bought didn't arrive until after I needed the cruiser on the road. I know the H55F is taller than the H41/H42. That would require modifying the transmission hump and possible the floor.

Great points and thanks for your Input help/advice. I’m picking up a 1982 H42 out of an FJ60 but it has a 40 top plate. The tcase is out of a 1980 Fj40 with build date of 1979 so has the axel ebrake. The only part of the puzzle that I wasn’t clear on is the transmission hump. If my existing one has enough height, I’ll simply weld up the two holes as @ToyotaMatt suggested. Then, I will see if I can get a cardboard template made from an H42 set up and cut two new holes for the shifters vs fabricating to fit.

I’ve not seen the condition of the transfer case or transmission yet. While it’s out of the truck, I will inspect and likely replace all bearings and seals.

I’m replacing everything:

Bell housing, 4 speed flywheel (resurfaced), pilot bearing, throw out, clutch pressure plate, friction disc, cover, fork pivot point (slave and master are new),machine shop will cut rear shaft and extend front once installed on truck (he would not build from measurements), speedometer gear (for 33” tires).

My last questionwhich I’ve not search for yet is the most desirable input shaft/output spline for 4 speeds?

 

[Ackcruisers]

Paul ,

you have a 1976 Global Spec. Body tub , however its for a 2F and optional H41 4Speed trans , you WILL have to completely weld up both

the trans and t-case shifter stick holes and relocate them , but the cover itself minus the 2 shifter holes should be the same H41 vs J30

trans options from : 9/72-12/78

i know others will chime in with more solid tech, this is all i know

Thanks, Matt. Following up to post links and images of the hump for my imported truck. According to EPC, my transmission hump should be part # 58262-90337 (blue circle) as shown here. For my FJ40 with 3 speed 9/73 - 1/75. The 4 speed option shows a different hump part number #58262-90341 (red circle). The only difference is the shift boot and thus hole location. The boot part numbers are here for 4 speed #58273-90300 and #58273-90301 for 3 speed. After close examination of the drawing of the hump in blue and red circle before, the red one looks to be slightly taller to accommodate 4 speed.

 

[Dizzy]

I've seriously considered the fiberglass reproduction hump (SOR). My hump gets way hot - it melted the original tar insulator pad at some point in the past, it is rusted and hacked up. So, I'm thinking that I might get cheap thermal insulation by doing less work, and get a cleaner final look then my attempts at repair.

 

[Living in the Past]

Found a thread I posted some transmission hump pictures of twelve years ago. First picture the left blue cover is from either a 77 or 78 US import. Shows how little different the transmission tower is, little to the left.The next just highlights the height difference change after the 72 until 1/79 when the tub was redesigned again.

 

[Living in the Past]

I have always assumed from 9/72-12/78 the height of the transmission cover was wether a three speed or a four speed. But have actually never verified it. So I dug out my four speed tunnel cover and measured it. By the color the best I can remember bought it in 1997 and was off a 78 model someone I knew was parting out. The 2/73 is mine. The height is the same. Just under six inches from the top to the flange. If the 76 with a three measures the same it will easily work with a four speed.

Here is a view of the two shifter openings. By the location of the transfer case opening and shape have to think Toyota just standardized for the three and four speed some time after the US only got a four speed.

 

[Living in the Past]

Great points and thanks for your Input help/advice. I’m picking up a 1982 H42 out of an FJ60 but it has a 40 top plate. The tcase is out of a 1980 Fj40 with build date of 1979 so has the axel ebrake. The only part of the puzzle that I wasn’t clear on is the transmission hump. If my existing one has enough height, I’ll simply weld up the two holes as @ToyotaMatt suggested. Then, I will see if I can get a cardboard template made from an H42 set up and cut two new holes for the shifters vs fabricating to fit.

I’ve not seen the condition of the transfer case or transmission yet. While it’s out of the truck, I will inspect and likely replace all bearings and seals.

I’m replacing everything:

Bell housing, 4 speed flywheel (resurfaced), pilot bearing, throw out, clutch pressure plate, friction disc, cover, fork pivot point (slave and master are new),machine shop will cut rear shaft and extend front once installed on truck (he would not build from measurements), speedometer gear (for 33” tires).

My last questionwhich I’ve not search for yet is the most desirable input shaft/output spline for 4 speeds?

I would prefer a coarse a output shaft but good luck finding one for an H42. Believe all those were H41s. By far the most common is the fine spline input shaft. The flywheel and clutch were just a change not three or four speed parts. Everything just needs to match.

 

[Ackcruisers]

I have always assumed from 9/72-12/78 the height of the transmission cover was wether a three speed or a four speed. But have actually never verified it. So I dug out my four speed tunnel cover and measured it. By the color the best I can remember bought it in 1997 and was off a 78 model someone I knew was parting out. The 2/73 is mine. The height is the same. Just under six inches from the top to the flange. If the 76 with a three measures the same it will easily work with a four speed.View attachment 2407575View attachment 2407578

Here is a view of the two shifter openings. By the location of the transfer case opening and shape have to think Toyota just standardized for the three and four speed some time after the US only got a four speed.
View attachment 2407581View attachment 2407586

This is very helpful. Appreciate you taking the time to do the measurements. When I’m back to my shop ( in White Mountains of NH this week), I’ll measure my transmission cover to compare and will post results. Based on your photos, it appears the only modification needed to drop cover over the new H42 is the round gear shift hole. My tcase shifter is late model configuration as shown below.

 

[Ackcruisers]

I would prefer a coarse input shaft but good luck finding one for an H42. Believe all those were H41s. By far the most common is the fine spline input shaft. The flywheel and clutch were just a change not three or four speed parts. Everything just needs to match.

Thanks for saving me time. Cruiser Outfitters link here has a number of input/output shafts. When we reference ‘coarse‘ is it 10, 16 or 19 spline? Assume it is 16 since 10 spline is coarse but only for 3 speed. My existing flywheel is 4 speed with matching clutch components. Here is link to my previous post.

 

[Living in the Past]

Thanks for saving me time. Cruiser Outfitters link here has a number of input/output shafts. When we reference ‘coarse‘ is it 10, 16 or 19 spline? Assume it is 16 since 10 spline is coarse but only for 3 speed. My existing flywheel is 4 speed with matching clutch components. Here is link to my previous post.

The 10/16/19 refers to the transmission output shaft. Three speed and a very few four speeds were 10 spline. 16 spline is the four speed mated to the one piece transfer case. 19 spline is four and five speeds mated to the spline transfer case. The 16 spline four speed ended 7/80. The 10 spline three speed ended 9/82 from what I can tell. In North America the three speed ended early in the 74 model year. As for input shaft that depends on which engine it was built to mate to. F and H series engines during the 40 series years were the same. The B engine used a different input shaft. Longer and is fine spline. Buying one and a seller provided a picture it would be obvious which was from a B series engine.

Think I committed on the four speed bellhousing/clutch in another thread. Technically you just have the correct flywheel/clutch for your year. Not sure the change was the same date in all markets but in the US the change was after the four speed was being used here. Australia had the four speed in the 73 model. 9/72 the hump and floor section in the 40 series changed. Because of the the hump change the fuel capacity was reduced by two gallons. Even those with a three speed had the smaller tank because Toyota only made one style hump. This why it's easier to put a four speed in 9/72+. I did a four speed in my 68 FJ40 back in the nineties. Was harder than just gathering parts. Depending on flange pattern on your transfer case and diffs may be possible to just buy four speed driveshaft and bolt them in. Plan on my three speed is for 76-78 front disc brake axle O already have and same year rate full floating rear axle need to get shipped from Australia. Instead of a H55F will use a Fairey overdrive. Mainly because I have one and other than a hole in the tunnel cover it will require no other mods.

 

[2countryhicks]

Alright fellas....I don't want to hi-jack the thread, but I have a similar situation that I am trying to solve. I have a 1973 FJ40 (Build date is 9/72) I am running the original F engine, but swapped a 4 speed trans (bellhousing,clutch, flywheel...) in. Now I am actually using my '3 speed' transfer case, driveshafts, axles etc. So, will my factory hump have clearance issues? I'd test fit it, but frame, axles, engine, trans etc are assembled on one side of the shop, and the tub is in my rotisserie!

 

[73FJ40]

@2countryhicks

Did you have your driveshaft lengths altered to accommodate the longer 4 speed tranny?