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BJ40 4-Speed to 5-Speed Conversion

shafiq

New Member
Joined
Mar 22, 2016
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36
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uk
Would like to hear from anyone who has successfully completed a 4-speed gearbox conversion into a 5-speed gearbox.
If so, what was the improvement and are there any long term issues with any of the components used to align the system?.
What speed difference has been noted on the B Type Diesel engine?
 
I haven't done this conversion but there are a couple of items to be aware of:
If your current handbrake is behind the transmission, it will, probably, need to be moved to the axle - change of back plates, etc.. However, I vaguely remember that LX had h/brake on the rear axle.
From the year in your intro, you have a 3B engine, The spline on the 5 speed g/box is 1.5 inches longer and has 21 splines. Boxes that fit F and H series engines have 10 splines and are short, Although boxes from 2H engines should fit.
Gearbox code numbers: 4 speed = H42 5 speed H55F

Regards,

Rodger
 
I haven't done this conversion but there are a couple of items to be aware of:
If your current handbrake is behind the transmission, it will, probably, need to be moved to the axle - change of back plates, etc.. However, I vaguely remember that LX had h/brake on the rear axle.
From the year in your intro, you have a 3B engine, The spline on the 5 speed g/box is 1.5 inches longer and has 21 splines. Boxes that fit F and H series engines have 10 splines and are short, Although boxes from 2H engines should fit.
Gearbox code numbers: 4 speed = H42 5 speed H55F

Regards,

Rodger

Hi Rodger, No i don't have the 3B engine its the B type only.
 
Oh that's interesting...
According to the info I have they stopped fitting B engines to 40s in 79/80. 2Bs were fitted between 79 & 81 and then 3Bs were fitted from 81 to the end of the production run. If memory serves your intro said it was a 1984 model, so some investigation may be necessary.

Regards,

Rodger
 
Hi good looking cruiser you have I have put A HJ60 engine and 5 speed box in my fj45 good mpg change the propshafts.
 
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