Marks Transfer Gears

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audaciousduo

audaciousduo

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Jul 28, 2007
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So I've got my Aussie lockers in and tested over two days of wheeling. Wow! What a difference. You can check out our trip videos buy searching audaciousduo on you tube there are quite a few. The next mod I'm after is a lower crawl ratio and I think I'm leaning toward the Marks transfer case gears. Even with my 370:1's I can use the 305:1 gear set and end up with a 55:1 crawl ratio. For the wheeling that I do this is sufficient. Now the big question for the 70 guru's out there. I have a 1985 BJ70 Canadian spec cruiser with a 3B and a 5 Spd. Do I have a 34 mm or 38 mm Idler shaft?

Thanks in advance

Dave
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You should just crawl under your truck and measure it. The changeover date is the 10th month of 1985.

I have these gears in stock...


~John
 
Radd Cruisers said:
Which trail are you doing in the picture? It looks quite familiar...


~John
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Sunrise lake. The V-Rock section. I'll see if I can figure out hat I'm measuring down there. I've never rebuilt a land cruiser T-Case but I've done a few Rover ones so I should be able to pull it off.

Thanks
 
bj70_guy said:
Can you PM me a price please?
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I don't do PMs on 'Mud because it creates too much email traffic for me.

Please email me via my website or call my business number 250 597 2500.

~John
 
The question is are you going to go 1to1 high or 108 to1? If your axles are 3:70 it might be a good idea to go this way especially with bigger rubber on it.
 
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I installed the Mark's gear set into Coleman (will follow up in my build thread soon) just over week ago and it makes a world of difference in the low range. I went with 1.00:1/3.05:1 ratios.

I did a snow run on Remembrance Day to go up to an aircraft wreck where an air crew lost their lives in 1941 and the gears really helped make forward progress in the snow a lot better (where slow speeds can make all the difference).

The gear whine is noticeable, but not that bad in high range. In low range it's more pronounced. With better sound insulation, the whine would not be bad at all. I have yet to use the recommended gear lube and that is supposed to reduce gear noise quite a bit.


~John
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audaciousduo said:
Sunrise lake. The V-Rock section. I'll see if I can figure out hat I'm measuring down there. I've never rebuilt a land cruiser T-Case but I've done a few Rover ones so I should be able to pull it off.

Thanks
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The idler shaft protrudes through the rear t-case cover and a segment is cut out for the lock tab. Easy to see (rusty end since its exposed). Measures O.D. should be 38 mm, or if you have the earlier one its 32mm. Here is a picture of mine with the back off.

If you have 3.70 diffs, I think you want to go Marks 3.05/1.08, like Aaron suggests. The 8% under drive will help compensate for larger tires and your relatively high geared diffs.
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With over 50,000kms since the Marks Transfer Case installation (gears were already set-up in split case) it is definately quieter, either that or I am more deaf lol. The lower range makes all the difference.
As we speak I am deciding to go Toy Box / with the Marks case ( because of the added strength of the Marks gears) The LOWER RANGE makes all the difference when it comes to quality wheeling.
 
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Nothing good to add here, but if done, please post up thread on install, I have been sitting on my marks gears for 4 years to install in future project.
Cheers,
Deny
 
Deny said:
Nothing good to add here, but if done, please post up thread on install, I have been sitting on my marks gears for 4 years to install in future project.
Cheers,
Deny
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Will post up soon, it's just that each time I try to get to it, something else comes up...


~john
 
for Jack @ Overland International who's installing Mark's Gears he got from Radd Cruisers in to his LJ78 5 speed.




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The gear clusters in place.

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The new counter shaft that uses tapered roller bearings.


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Clearancing the outer case for the taller output gear. Not all cases seem to need this clearance created.

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Comparing stock gears side by side to the Mark's Gears with 3.05:1 low range vs. the lare BJ74 Automatic 2.296:1 low range gear set.

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The
 
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How the counter shaft is retained at the back of the transfer case.

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Later, I went to the lower high range option 1.08:1 for the better acceleration with 33s or 285 75R16s - the BJ74 automatic is fairly tall geared... Here I'm removing the high range output gear - it's a single gear swap to go from 1:1 high range to 1.08:1 high range


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The gears show barely any wear for having been in place for about 5 years.

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The counter shaft uses small plastic shims to set the pre-load of the counter shaft bearings.


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Radd Cruisers said:
I installed the Mark's gear set into Coleman (will follow up in my build thread soon) just over week ago and it makes a world of difference in the low range. I went with 1.00:1/3.05:1 ratios.

I did a snow run on Remembrance Day to go up to an aircraft wreck where an air crew lost their lives in 1941 and the gears really helped make forward progress in the snow a lot better (where slow speeds can make all the difference).

The gear whine is noticeable, but not that bad in high range. In low range it's more pronounced. With better sound insulation, the whine would not be bad at all. I have yet to use the recommended gear lube and that is supposed to reduce gear noise quite a bit.


~John
View attachment 372660
Click to expand...

Whats the recommended gear lube I had great results with redline shockproof heavy 70/250 w on my 6 speed Harley
 
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