TH400 Front Pump Replacement

[Jon87V20]

Hello!

1987 Suburban V20 350/TH400/NP208

I'm about 99% sure the issue with my TH400 is the front pump.

Does anyone know, can anything else become damaged from the pump not operating correctly for say a week or so of driving?

Basically, it was shifting funny for about a week, then it started making a loud whining noise when cold (it would clear up after a few minutes), then eventually it couldn't get to third gear while under load, was slipping etc. for about 15 minutes until I was home. It could still move it self when I parked it in the garage.

I'm trying to figure out if I can swap in a new pump and it'll be all good, or if I'll get it back in the truck and there'll be other damaged components as a result of the pump failure.

Thanks!

[VileZambonie]

Typically TH-400 pump failure is breakage not intermittent pressure. What you describe is either the result of low fluid level or it's most likely time for a rebuild. Replacing the pump without a diagnosis would not be advisable.

[Jon87V20]

Thanks, Vile.

Bummer I was hoping that's what it was. After looking around I found a video on YouTube, the guy had the same noise as I did and said it was the pump.

https://www.youtube.com/watch?v=lIqLVcuw31E

Is it a safe bet to pick up one of those rebuild kits on eBay?

I couldn't have someone else rebuild it for the foreseeable future due to my financial situation, but I don't want to let the truck die. My concern with buying one of those rebuild kits is I don't know if they come with everything, and the bad components may not be replaced in the rebuild.

I've also considered junkyard transmissions but I can't afford to pick one up from the yard and have it not work and have to get another one.

[VileZambonie]

Check the fluid level, if okay, drop the pan, check the filter and pick up tube/o-ring. Examine the contents of the pan. there's a good starting point for you.

[Jon87V20]

Ok I'll try that. Thanks for the help, Vile!