I still have this 1974 HJ 45 transmission with the bull low 1st. Anyone know this model? I tried it out and didn't like it. I t was like having a 3 speed and I took off in 2nd.
Hj45 transmission? Bull low 1st (6 Viewers)
- Thread starter Gas axe
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
I have had several USA 4 speed trucks with a granny low first - I think it was designed for field use working with tractors. Yes I just start my 84 F150 in second unless I'm on a grade with a load.
You have a H41 transmission which has a first gear of ca. 5:1. Swap in a H42 if you want a higher 1st gear.
- Thread starter
- #4
Thanks Godwin:
I went through this ID 15+ years ago here but forgot the model and gear ratios.
Living in the Past
SILVER Star
Did you ever post a picture. There is an early four speed with a 5.3:1 first gear versus the H41 that first gear is just under 5.0:1. 74. It's most likely is a H41 but could possible be the early one that was used on 4/72-9/73 in HJ45.
I wish I had one that low, my low in my h55 is low but not as much.. if ya run 35 or 37 inch tires, it is needed.
Living in the Past
SILVER Star
H41 and H55F share the same first gear. Some GM four speeds like the SM420 and SM465 had a 7:1 ratio. Probably newer non Toyota have a lower first gear. H41/H55F are slightly lower than 5:1. The early Toyota four speed prior to 9/73 was 5.33:1. FJ25 had a 5.4:1 four speed. Only third and fourth gears were synchronized.
They are up to 4:1 low gears for the split transfer case. If you want lower for the street diff gear change is an option for that.
Thank you for this. I was not aware.. Good Info..
pb4ugo
SILVER Star
Fyi, for clarification the SM420 has 7.05:1, the SM465 has 6.55:1. When you have a heavy load in the bed, a heavy trailer or a technical section on the trail you'll be glad you have a lower gear.
H41 for the win!!! I think there a few ways to tell if you have the early 4 speed that has 53:1 ratio. I believe the easiest way is look at the top plate cover of the transmission. If it's a solid piece of cast iron, then it's the early style. I'll post pics later on
If it's a two piece top plate (looks just like an h42 cover) and you know you have granny gear, then it's a later style h41.
If you have it taken apart, look ay the rear output shaft and count how many splines you have. Early style has 10 splines.
Lastly, you can put it in gear (I think it can only be done with transmission out to make it easy) and count how many revolutions of the shaft it takes for 1st gear to make a complete turn. The early ones will take 5 full rotations plus 1/3 of another full rotation (5.3 gear)
Yes, they drive like a 3 speed if you only use 2nd, 3rd, 4th gear. 1st is pretty useless on the street since you only go about 10ft before shifting.... But, if you go off roading, it's good. Also, I like to just find a random steep hill near my house, put it in 1st gear, and let go of the clutch pedal. I don't even give it gas and it climbs up the hill no problem. Slowly, just at idle speed and I don't even have 4x4 engaged at that time. Now thst is awesome.
Essentially, its a little bit as "twice as slow" as a regular 3 speed
If it's a two piece top plate (looks just like an h42 cover) and you know you have granny gear, then it's a later style h41.
If you have it taken apart, look ay the rear output shaft and count how many splines you have. Early style has 10 splines.
Lastly, you can put it in gear (I think it can only be done with transmission out to make it easy) and count how many revolutions of the shaft it takes for 1st gear to make a complete turn. The early ones will take 5 full rotations plus 1/3 of another full rotation (5.3 gear)
Yes, they drive like a 3 speed if you only use 2nd, 3rd, 4th gear. 1st is pretty useless on the street since you only go about 10ft before shifting.... But, if you go off roading, it's good. Also, I like to just find a random steep hill near my house, put it in 1st gear, and let go of the clutch pedal. I don't even give it gas and it climbs up the hill no problem. Slowly, just at idle speed and I don't even have 4x4 engaged at that time. Now thst is awesome.
Essentially, its a little bit as "twice as slow" as a regular 3 speed
