New 6.5 Suburban/ leaking transmission

[AugustDiesel]

Good evening all.

Just purchased an 88 1/2 ton 4x4 suburban with 3/4 ton axles and a 6.5L GM Goodwrench diesel. Wanted to take a moment and introduce myself and go ahead and start asking questions. I'm quite familiar with the diesel suburbans, this is my 3rd one.

It seems that, when in reverse gear, the transmission pours out transmission fluid. Only when in reverse though. Does not leak when driving in forward gear. Any idea what causes this or what seal needs to be replaced?

Thanks, Andy.

[rustyk]

From where is it leaking?

[Robyn]

Which tranny is in the beastie ???

1/2 ton would have a 700R4

Get some help.

Block the wheels

Set the park brake.

Have helper operate the thing and place it in reverse while you watch to see where the oil is coming from.

Good luck and be safe.

[AugustDiesel]

Thanks all. Looks like there are two broken bolts in the transmission oil pan causing a break in the seal: one in front one in the rear. When in reverse, the fluid pours out near the rear broken bolt. Got a deep dish aluminum oil pan on order and a friend to help me drill out the broken bolts and button this thing up. New filter, new gasket, and synthetic oil along with the new pan and new bolts ought to help this tranny along nicely. It's a 700R4 btw.

[DmaxMaverick]

Broken tranny pan bolts are usually very easy to remove. Once the pan is out of the way, they can typically be removed with fingertips or screwdriver, or at the most, a left-hand-twist drill bit. If it's tight, a light tap with a punch will usually loosen it. Often, folks overkill it, and damage the threads.

[Robyn]

Surprising that bolts are broken off ???

Normally the aluminum pan rail will strip out long before the bolts break.


Hint

Use the composite type "cork" gasket.

The neoprene ones are worthless.

Make sure the pan rail is clean and dry (Brakekleen on a rag works great)

Good luck :)

[AugustDiesel]

Surprising that bolts are broken off ???

Normally the aluminum pan rail will strip out long before the bolts break.


Hint

Use the composite type "cork" gasket.

The neoprene ones are worthless.

Make sure the pan rail is clean and dry (Brakekleen on a rag works great)

Good luck :)


Thanks Robyn! Where might I find that style gasket?

[AugustDiesel]

Here are the photos I have btw. Will get more later. I have named it Rusty, because well, it's a Kansas rust bucket. But the drivetrain and frame are solid. Already cut out the rear drivers wheel well to reduce tetanus risk ;) 3417

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