t/case weak link?

Started by VueDoo, February 07, 2004, 02:04:25 PM

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VueDoo

What would be the weak link in a marlin 4.7 21 spline single case? input shaft, output shafts, gears, the case itself, other? Are 4:1 gears still avail? are they stronger?
I'm wondering what will break with a V-8, sm465, d60, 14b, 42" swampers, and a idiot driver :headshake:
I think a 205/203 doubler might be strongest, but a toy case is going in.
Thanks, Phil
I spent most my money on booze, broads, and 4x4's; the rest I wasted!

84runner

If you can go with the 23 spline do it
RUBICON TESTED BIG BALLS APPROVED

VueDoo

Is the input the weak link?
I spent most my money on booze, broads, and 4x4's; the rest I wasted!

Marlin

Quote from: VueDoo on February 07, 2004, 02:04:25 PM
What would be the weak link in a marlin 4.7 21 spline single case? input shaft, output shafts, gears, the case itself, other? Are 4:1 gears still avail? are they stronger?
I'm wondering what will break with a V-8, sm465, d60, 14b, 42" swampers, and a idiot driver :headshake:
I think a 205/203 doubler might be strongest, but a toy case is going in.
Thanks, Phil

As long as the input is a Japanese made total spline gear, the rear output shaft would be the weak link. We have never had a input failure! Running a V8, granny box, and big tires, and if the gears are my old americian design, we had many failures (just one of the reasons I finally choise to go with the orginal gear cutter) and the 4:1 AA gears break even easier? I think the 4:1's are made from a less expensive material? I would advise using a 81-85' output shaft and polishing it at the ruff area just in front of the front output splines.
Do your best to keep the buggy as light as possible. This will put less stress on the drivetrain.
Let me know if you need a polished output shaft.
Why are you still running a 21 spline input? You know you should be using a 23 spline input :_oops:


Marlin
1980 Toyota - 1997 3RZ-FE 2.7l Engine, Turbo R151F 4.31:1, Triple Turbo Marlin Crawler Billet (2.28x4.70x4.70) = 1,148:1 Crawl Ratio, Marlin Crawler Twin Stick and Short Throw Shift Kits, 30mm H/D Output Shaft, High Angle Drive Lines, 5.29:1, ARBs, High Pinion Front, 25mm HD Billet High Steer Kit, 6 Pin Locking Hub Bodies, 86+ Wide Rear End, V6 3rd member, Chromolly Axles all around, 37" IROKs with Beadlocks, York onboard air - Rollbar air tank, Premier Power Welder, Marlin Crawler 4" USA-made Leaf Springs, Bilstein Shocks, et cetera....

VueDoo

Thanks Marlin, thats the info I was looking for. This is for a different project, not the comp buggy.  If the rear output is the weak link with a total spline 21 , then would there really be any advantage to a 23 spine other than piece of mind?
I spent most my money on booze, broads, and 4x4's; the rest I wasted!

Marlin

Quote from: VueDoo on February 11, 2004, 01:07:54 PM
Thanks Marlin, thats the info I was looking for. This is for a different project, not the comp buggy.  If the rear output is the weak link with a total spline 21 , then would there really be any advantage to a 23 spine other than piece of mind?

You are correct Phil :bowdown:The only other reason is that the larger 23 input has more surface area, so there would be less spline wear thur the years.

MC
1980 Toyota - 1997 3RZ-FE 2.7l Engine, Turbo R151F 4.31:1, Triple Turbo Marlin Crawler Billet (2.28x4.70x4.70) = 1,148:1 Crawl Ratio, Marlin Crawler Twin Stick and Short Throw Shift Kits, 30mm H/D Output Shaft, High Angle Drive Lines, 5.29:1, ARBs, High Pinion Front, 25mm HD Billet High Steer Kit, 6 Pin Locking Hub Bodies, 86+ Wide Rear End, V6 3rd member, Chromolly Axles all around, 37" IROKs with Beadlocks, York onboard air - Rollbar air tank, Premier Power Welder, Marlin Crawler 4" USA-made Leaf Springs, Bilstein Shocks, et cetera....