Transmission Brake Conversion SJ 413

Starts at the flywheel, ends at the hubs, any problems along them lines, ask your questions here.
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Grey Man
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Transmission Brake Conversion SJ 413

Post by Grey Man » Thu Aug 25, 2022 10:55 am

Hi,
The rear disk conversion is one of the many jobs to do on my SJ 413. I have been offered a transmission brake drum, backplate (incl mechanism) and cable. Any advice on what to watch out for (its not cheap) before I commit. I have read through one of the posts but would be interested to know if anyone had to shorten the prop to get it to fit the drum after the drum was fitted?

Cheers

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ScottieJ
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Re: Transmission Brake Conversion SJ 413

Post by ScottieJ » Fri Aug 26, 2022 9:49 pm

Does your SJ have the smaller yoke props with M8 bolts (12mm nuts)? It will need them for the transmission brake.

Depending on your handbrake lever set up you might also need to make a small modification to connect it to the cable and also make a mount to hold the cable outer (I’ll take some pics of what i did on my LWB for you)

Out of interest how much are they asking for it? I know someone that has quite a few so might be able to save you some £
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Re: Transmission Brake Conversion SJ 413

Post by Grey Man » Mon Aug 29, 2022 10:25 pm

No unfortunately not. Its a 1989 SJ413 and the yoke spacing between holes is 61mm +/-1mm. The drum/backplate/mechanism/cable I purchased for £40 came off a SJ410 and the spacing between the studs on the drum is 57mm +/-1mm. So I bought the SJ410 prop shaft to fit the drum. The longer section of the prop is reasonable but the UJ at the shorter end was in poor condition, so I left it at the scrapyard. My SJ413 short section of the prop shaft (female) fits the splines on the long section of the SJ410 prop shaft (male), therefore I have a prop shaft with different yokes to fit the tran brake drum (SJ410) and my existing axle (SJ413).

However, it means that I can only fit the prop shaft with the long section connected to the transfer box (opposite to how it was when I removed it) and I'm not sure what effect this will have on the durability of the prop long term or the movement between the diff and transfer box when riding uneven ground - any advice cheers.
The UJ in my unused SJ413 section of prop is new and I was going to remove and replace the older one in the SJ410 yoke with mine, do you know if they will fit - they both measures the same with a standard steel mm rule - any advice cheers.

Any photo's of brackets/supports, and/or cable route would be appreciated.

Hope the above explanation was not to long winded.

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ScottieJ
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Re: Transmission Brake Conversion SJ 413

Post by ScottieJ » Tue Aug 30, 2022 1:20 pm

The UJ sizes should be the same so you could just swap the smaller yoke onto the end of your prop shaft. a 410 prop will also be 25mm longer so unless you have suspension lift you might bottom out the prop shaft at the splines over bumps and this could break/bend tbox mounts.

The orientation of the prop doesn’t matter too much really.

I presume your 413 is a samurai then if it has the larger flanges. Didn’t manage to get any pics over the weekend but I’ll get the LWB back on the ramp this weekend and grab some pics.
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Re: Transmission Brake Conversion SJ 413

Post by Grey Man » Tue Sep 06, 2022 8:42 am

Cheers for the advice. A local small engineering company are going to swap the 413 and 410 flange and insert my 413 UJ to the 410 flange. That way the propshaft length should be no different. Going to have a close look at the tran brake cable to day and see what i need to to do.

Cheers

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