Squealing turbo 400

[73 cheySuper]

cheveslakr​

Veteran Member​

Senior Member

• Yesterday at 8:27 PM
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• #1

I thought I had the solution, but failed. The turbo 400 in the K20 squeals like a wicked loose belt under acceleration, gets louder the more load it sees. It's fine around mild load.
Thought it was the clearance between the flex plate and the starter pinion, but I increased that to 1/8 inch or so and no change. Also, no evidence of interference on either gear. I also was running it on cam break-in till I got maybe 2 miles on it with maybe 2 or 3 quarts low. Topped it off after it was warmed and it may have curbed the noise just a tad. I'm thinking it's the pump, but there's maybe more possibilities?? This trans was sitting for a decade, no clue on the condition other than the fluid looked and smelled just fine. I of course changed the fluid, and filter. What I didn't do is pull the old filter seal out, because it looked fine. I hear that could effect fluid pressure if its compromised in any way. I hate the idea of pulling this thing out, it'll be a major pain. Can a pump be replace by just sliding the trans back far enough to remove the converter?? I'll likely have a chat with a trans guy later today, but the last guy quoted me $3000 to rebuild this thing, and that's insane.

 

[NickTransmissions]

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Can a pump be replace by just sliding the trans back far enough to remove the converter??

lol, No. The pump cannot be removed in that manner. Replacing the pump requires front end play to be checked again to confirm it’s within spec. The unit will need to come out for overhaul if the sounds, as described, are coming from the transmission.