Bj40 upgrade how many parts from Bj70

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May 8, 2011
Hi Guys,

I am restoring a Bj40 and I want to take parts from a Bj70 and put them on the Bj40 can I use the disk brakes from the Bj70, also I am thinking of using the 3B engine and 5speed tranny from the Bj70. I realise that I will have to change the mounts on the bj40 frame and modify drive shafts. Is this easier than fitting the 5speed tranny on the Bj40s B engine. Also I want to use the power steering system from the Bj70 on the Bj40. Is this possible and are there any other parts that would be useful that I have not thought of. Any help is appreciated. Thanks in advance.
the most difficult part will be fabricating the bits for the power steering gearbox to mount it to the 40 frame. your bj40 engine side mounts will bolt to the 3b and drop right into the bj40 frame without modification. if you want to use the 5speed however you will need to fabricate a cross member under it. This is assuming your bj40 was built prior to 1981 or so. the disc brake bits will fit onto your bj40 axle if you reuse the bj70 knuckles and outer cv joints.
Roma thank you very much for your suggestions, my Bj40 is 1983 and the Bj70 is 1986. I will have to offer the 3B engine up to the Bj40 frame and see if you are correct, hopefully you are. Is it a straight forward fit of the Bj70 knuckles and outer CV joints to the BJ40?
you may need to remove about 3/4 inch of metal from the inside of your birfield (CV) housing to fit the disk brake birfield in. however since your bj40 is an 83 model it may already have sufficient clearance. since so many markets received changes in different years I cant say with 100 percent certainty on that. It will either be easy (take ten minutes of grinding) or easier and it will slide right in. also since your bj40 is an 84 model there is a very good possibility it already has the proper crossmember in place. if you want to put up some pictures that would help. in most markets the 40 series had the split style transfer case by 1981. if that is the case you can probably just move it back 3'' to make up for the additional length of the 5spd. also does your bj have the parking brake on the axle or on the driveshaft? would help to know what market the cruiser is or what country you are in.
Why not use the 70 axles, engine and trans under your 40?
Hi all,

The power steering on the 70 Series is the same as the 60 Series. Search here on MUD for "60 Series PS" to find out about this conversion.


Thanks guys this is great, my Bj40 is an Irish Bj40 I will take some pics and put them up tomorrow. The use of the 70s axles sounds like a good idea, I wonder is it a straight forward swap, is there much welding/modifications needed?

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