Leak from top of transfer case… still leaking after replacing gaskets (1 Viewer)

[Ollie88]

Folks,

I just had my gearbox and transfer case pulled by a local shops as I had several leaks coming from my transfer case. Just got it back and it still appears to be leaking from the top of the transfer case, very annoying… not sure if the garage replaced that gasket or might have forgotten it.

Any idea whether this is a common leak and where I should look for the fix? I want to be crystal clear to the mechanics this time so they know where to look.

Thanks all

 

[Skreddy]

It’s probably that gasket or the shift shaft seal.

 

[pjohnson]

Well, based on greasy dirt and general lack of cleanliness, along with the inappropriate use of silicone sealer on the idler shaft, I doubt they did anything at all except smear on the silicone.

 

[B y r o n]

Did you/they bother to check the case for cracks?

 

[sodafeld1]

Looks like a rubbish job they did.

 

[Paul_A]

Looking closely at the oil slick I see a hairline of what might be a crack reaching down to the web in the casting. It looks like it is weeping oil. If you click on the pic you can zoom in and see it better.

 

[Ollie88]

Well, they actually did do something right which was remilling synchros so it doesn’t grind into 3rd and 4th gear, that went well. But I also asked them to replace all seals in the transfer which did not have seem to go to well.

I just took a better look and some pics and YES there’s a crack in the transfer… damn. Can you aluminium weld this? I live in Colombia, so labor isn’t the problem but parts are.

Btw I was the one that smeared some picture on the idle shaft, wanted to rule that one out and heard stories it can sometimes still leak after replacing the o-ring.

 

[Ollie88]

Edit: I heard that JB Weld has some putty that might hold for a little while, anyone ever tried that on a leaking T-Case?

And curious to hear if TIG welding is a good idea?

 

[sodafeld1]

Very hard to repair dirty aluminium, it is porous and each pore holds dirt and grease. Best of finding a second hand case in good condition case really.

 

[peesalot]

You could possibly weld/tig it, grind it all out and spend time slowly stiching it up, I agree with previous post that once torn down a good case would be better but if it just isnt a possible then tig it up. The cases crack when wheels tires are bound up and driver just keeps hammering it or when starting with a heavy load. IMO even if tig/mig fixed the stress points at the edge of weld will be potenial weak points to begin new cracks. DO NOT DRIVE IT like that, it will split the case in half. Usually those cracks run right to the idler. The Orion case from AA is a bolt in and is iron, no cracky.

 

[Ollie88]

Thanks @peesalot ! That's very helpful. Im going to bring it back to the garage tomorrow and see if they can TIG weld it.
Just one question, what do mean with the case cracks when "wheels tires are bound up and driver keeps hammering it"? I have done some proper offroading so far but nothing too harsh or unusual for an FJ40...

 

[pb4ugo]

I've split several tcases in 1/2 and when they break in 1/2, they seem to follow similar lines like that crack. That case looks like it will eventually do the same. I'm not sure I would waste my time trying to weld that crack.

 

[peesalot]

The aluminum case is not a straight thru design for rear output. The front & rear output are offset so all torgue, wether climbing, starting from a stop, or pushing tires up an obstacle is trying to rotate that case, if the output shaft wont spin something has to give. Now most people stop when the vehicle wont move, some dont, also, starting from a stop on pavement with a heavy load or tow can exhibit the same force. If the idler cant rotate the output gear the force will push it away as the gear teeth are helically cut , a straight cut gear wont do that but it also wont handle the torque and is loud as s***.

 

[Ollie88]

Okay thanks guys, that's helpful feedback. Sounds like I should start by looking for a T-case replacement...

 

[Living in the Past]

The aluminum case is not a straight thru design for rear output. The front & rear output are offset so all torgue, wether climbing, starting from a stop, or pushing tires up an obstacle is trying to rotate that case, if the output shaft wont spin something has to give. Now most people stop when the vehicle wont move, some dont, also, starting from a stop on pavement with a heavy load or tow can exhibit the same force. If the idler cant rotate the output gear the force will push it away as the gear teeth are helically cut , a straight cut gear wont do that but it also wont handle the torque and is loud as s***.

The 40 series one piece case came behind low power straight six. When the four speed started Toyota changed the low range gearing with wider gears. Open diffs, 29" tall skinny tires is how they came from the factory.

Switch to a V8, add traction and lower gearing in the diffs, larger, wider tires with aggressive tread and twin shift that allow low range 2WD all put more strain on the transfer than Toyota designed it for. Never ran bigger than 31" tires. Eevn with Lock Rights I have never cracked a transfer case. But I am careful on the skinny pedal. Stop moving the solution is not to push the skinny pedal harder. The 8/80 switch to the split transfer case was a big improvement over the one piece case