A745 Trans Rebuild?

Hey all,
I have an A745 3-speed manual in my van and I'm pretty sure the front input shaft bearing/seal is bad. It shifts fine but at a specific rpm, around 2800, I can hear a roaring noise coming from the trans... it leaks out of the front as well as I can see it on the bottom of the bell housing. Fluid is clean btw.

So, from what I know, the fix is to put a bearing/seal kit in the trans and the kit runs about $200 for the parts, is that right? I have a local guy that's done engine/trans work for me in the past that says he can do the bench work if I take it out for about $400 (if nothing else is wrong in there).

I called a local "big box" trans place and he wanted $1200 which is about what I expected from them.

I also found a used trans out of a '66 A100 for $75 that's not far away. I'm torn on whether to swap it out with the used one and see what happens or just drop mine and have it rebuilt for $400... idea's, comments?

eta: anyone got a link to the bearing kit?

Good ideas:
It's not the rear main seal (luckily), it's 90w gear oil, I've taste tested it already to rule that out.

Trans mount looks good, checked it as well.

It doesn't make the noise at idle or off-idle, only in the top of each gear and it will get constant at about 60mph (at about the same rpm as the top of 1st and 2nd gear), it sounds "whiney". It's not the throw out bearing and it shifts fine.

If you push the clutch in going down the road while it's whining it will subside somewhat but not go away until rpm drops enough to get out of the affected range.

It "might" be the front u-joint making the noise (it's the old slip pot type), I'm going to open it up on Saturday and grease it really well and see if that helps. I suspect the brass input shaft bushing in the back of the flywheel might be shot as well, that might cause some of this type of thing.

I just had the rear axle bearings done a month ago and the noise was present before then too

Any idea where I can get the oil seal for the front? i was expecting I'd have to buy the whole kit to get it...

eta: O'reilly has the seals,

That old front u joint if it lets go it feels like you have four flat tires. Not too much to them as far as internal guts to make a winding noise. Mabee its your ring and pinion howling and the drive shaft is amplifing it.

Now that you mention that you still have the ball and trunnion instead of a slip yoke/u-joint up front that is where I would say the noise is coming from. Before I change mine I had a lot of noise above 50 mph. Cost me about $200 at the drive shaft shop to covert it and rebalance the shaft.

ok, got a small update.

I dropped the drive shaft and checked the ball-n-trunnion joint in the front and it looks good, full of good clean grease and it moves ok.

I drove it a lot and paid attention to it this weekend and I can hear the noise faintly when it's at idle, with the clutch both in and out. If you rev the motor it gets louder as the rpm's increase, it gets really loud over 2500. I'm kind of suspecting the throw out bearing but it isn't really acting like that (it should stop making racket when the clutch is in).

It does sound like metal-on-metal though, just like a bad bearing that doesn't have any lube in it (high pitched whining/grinding).

I guess I'll have to get under it while it's running (preferably on a lift) and see where it's coming from.

It looks like the classic symptoms are:
Whining when you are standing on the clutch: Throw out bearing
Whining foot off the clutch in neutral or in gear while driving it: Input shaft bearing

Mine whines for both of the above... I guess the input shaft bearing is probably bad.

eta: just got off the phone with a shop that does performance transmissions, he says he thinks it's the pilot bearing in the back of the crank shaft. He's pretty well convinced me too, if he's right it'll only cost me about six bucks and some time

67a 100 pickup wrote:Now that you mention that you still have the ball and trunnion instead of a slip yoke/u-joint up front that is where I would say the noise is coming from. Before I change mine I had a lot of noise above 50 mph. Cost me about $200 at the drive shaft shop to covert it and rebalance the shaft.

hmmm, that could be it.

I checked the access cover on the bell housing and the clutch/PP/throw out bearing all look brand new (the previous owner said it was new, guess he told the truth there). Still got the noise... thinking it's the trans itself of the ball and trunnion.