I have an '88 300TE transmission that has an engine whirring sound to it. I've replaced the oil, filter, and K1 springs so it shifts fine but the noise remains and I'm afraid it can fail at any time. It only slipped once because oil was low. The engine is a 3.6L with more torque.

I'm considering:

* finding a '90-92 transmission with first gear start. What are the differences and will they retrofit...easily? Are these improved or stronger?
* rebuild a spare '88 transmission

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'88 300TE, 175k, black RENNTech 3.6L Recaro C's AMG 1 SOLD
'92 500E, 110k, Spruce green, stock SOLD
'94 E320 Cabriolet, 130k, E500 wheels, Emerald green SOLD
'94 E320 Cabriolet, 110k, black, stock, SOLD
'88 300TE, 229k, dark grey, SOLD
'90 300CE, 212k, white, new paint, SOLD
'91 300E, 209k, white, rebuilt head SOLD
'74 914-6, grey, 2.7L 325hp twin turbo Audi conversion