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Discussion Starter · #1 ·
Hi Everyone,
We’re having a problem with 2 things in our Rally Car (Jeep ZJ V8 5.9L).
1- We have a huge problem with our gearbox!!! Almost every race we need to change the gear box as it breaks either during the race or immediately after that. It may brake in the first 50km or less. Any ideas on ways to avoid this issue. Could we modify the car that other gear boxes for a different car or model fit in and last for longer?

2- Our front axles are sh*t!! We change them after every race. Is there any aftermarket front axles that would last longer? Or even any modifications or solutions?
Hope someone would be able to help.
 

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The poor gearbox is only really designed for road and slow off road use as its only classified as a light duty box and pretty much near its torque and load limits doing that, so basically you really need to fit a heavier duty model or treat it with a bit more care.

The Dana 30 front axle again is not designed to be raced off road and can be broken even when driven slowly off road if abused so you could fit Dana 44's from a wrangler, Toyota land cruiser axles or even Nissan patrol axles but most will require a full brake change and custom drive/prop shafts and a change of wheels used.

The 30 can be made to handle greater loads if you fit heavier duty shafts and brace the axle casing top and bottom but still will not cure it from breaking a ball joint/upright or even the carrier/gears if totally abused.
 

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Discussion Starter · #3 ·
The poor gearbox is only really designed for road and slow off road use as its only classified as a light duty box and pretty much near its torque and load limits doing that, so basically you really need to fit a heavier duty model or treat it with a bit more care.

The Dana 30 front axle again is not designed to be raced off road and can be broken even when driven slowly off road if abused so you could fit Dana 44's from a wrangler, Toyota land cruiser axles or even Nissan patrol axles but most will require a full brake change and custom drive/prop shafts and a change of wheels used.

The 30 can be made to handle greater loads if you fit heavier duty shafts and brace the axle casing top and bottom but still will not cure it from breaking a ball joint/upright or even the carrier/gears if totally abused.
Thank you for your response.
Do you recommend any transmission to fit in instead of the stock?
 

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Thank you for your response.
Do you recommend any transmission to fit in instead of the stock?
i am guessing your engine is modified
if thats the case
first take the engine to a test bench and get power output

Transmission have a torque rating
you need to choose one that match your engine output

larger tires will increase your gear box and axles stress
did you change ratio in the axles

the dana 30 have its limits you can find kits to reinforce then
but a swap for a better axle is the way to go

my 5.9 is a wotk in progress but power output is planned at circa 400hp
But i have not intentions to go rally it
 
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