TKO 600 oil leak at front?

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TKO 600 oil leak at front?

Post by 427dart » Sun May 29, 2016 8:53 am

Installed a TKO 600 trans in my '85 Mustang LX back in 2006 and now it has developed a leak around the bottom of bellhousing area.
Seems to leak while sitting as after a week of no use there is a small puddle of trans oil. Just noticed this in the last 3 wks.
Trans might have 6000 miles on it since install and has taken some drag race abuse behind my 427W. The 427 has been powering it for 6 years now. After researching I see that front seal leaks and possible cracks at front of trans are common.
Anyone else having issues with the 600?

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Re: TKO 600 oil leak at front?

Post by ChevyEFI » Wed Jun 01, 2016 7:03 pm

I don't know the Ford installs inside and out.
But an adapter plate offered for the TKO-to-Chevy bells had openings.
One of which was right in front of the countershaft bearing race. Which allowed the race to walk forward.

Other than that, I would say your guesses and normal diags. are in order.

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Re: TKO 600 oil leak at front?

Post by MadBill » Tue Jun 07, 2016 10:44 pm

The screw-in countershaft plug that can loosen and has an O-ring that sometimes gets pinched; perhaps yours has hardened up a bit and gone from marginal to oozing. If the box is overfilled or the car parked nose down, that can can be the final straw. Also the input shaft retainer bolts are prone to loosening which too can cause leaks.

One more: Many synthetic oils are better at finding their way through marginal seals/joints.
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.

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