This is cross posted so if anyone is also a Pontiac guy you might see it on another forum. Im having a little trouble here. My longtail th375 (the one that is in a 400 case not the 375B) in my wagon is dripping fluid right onto my H pipe from the seal that the driveshaft slip yoke goes into. Pretty common and something I have changed before, but Im struggling to find the correct one for the oddball th375. I dont want to get under there and pull the seal only to find I ordered the wrong one. First, Im not sure Im using the correct terminology. Is the one I am looking for the Output Shaft Seal, or the Extension Housing Seal? The ones listed for the extension housing seal often come with a bushing. So I don't think that one is correct. And then if anyone happens to know the correct part number for the one I need I would appreciate it. Would it just be a TH350 seal? I read that the 375 has a unique tail housing so I don't know if the seal is also unique.
Should be a TH350 seal. I have one of those housings....it uses the TH350 type yoke, not the bigger TH400 yoke.
Yeah. I knew the ID should be for a th350 slip yoke. my concern is that the OD of the seal would be different. I tried looking up a model in rock auto I thought may have come with a th375 but I didn’t have any luck. someone put a smogger olds 455 (not my choice) into my 1962 Catalina Safari. Probably the trans is from the same donor car.
There we go. I looked up 1973 vista cruiser and didn’t see one. The rest of us should have to pay into a Gofund Me account that pays you everytime you hand out useful information on here.
As far as the terms, you are working on the extension housing. Sometimes the housing bushing is worn and is part of the seal leak issue, hence the bushing & seal kit being available. If you don't have much yoke play you most likely don't need the bushing. But the rear seal has been called the rear seal, the output seal, extension housing seal, among others.
Okay, I just watched a video on that. Needs a special tool for the bushing removal. I’ve replaced the end seal on a couple TH400s but I’ve never replaced one of those bushings before. Maybe I will just buy one of the kits and removal tool and do both. edit: or maybe not. That bushing removal tool is expensive.
I'd see how it fits first...if you can feel side play on the yoke, more than just a few thousandths of an inch, then you might want to change the bushing. But you'd also want to inspect the yoke first, see how worn it is. I've never replaced a bushing without removing the housing, but then I have a set of bushing drivers that I can use to replace bushings, without the shaft in the way.
I already had the pinion seal for the 9.3. So now Ill just pull the whole draveshaft and change the seal on both ends. Pinion seals are the bane of my existence. Every old car I have ever bought had a leaky pinion seal. Two of them on a couple of 4x4s Ive had. To be honest my bigger concern with the driveshaft is engagement of the slip yoke. There is a lot of yoke showing. Im not sure how much is getting inside the trans. If it were a th400 I wouldn't have driven it, but I think this yoke is longer than a short tail th400 slip yoke that I am used to seeing. Either way Ill check it when I replace both of these seals. Worst case the DS is a couple inches too short and I get a new slip yoke anyway with a new shaft The whole thing is a franenstein swap at this point so I don't know what kind of corners were cut.
Well, if in fact you have no where near enough yoke in the transmission, that certainly could be part of your seal failure. And if it turns out that you are correct about the yoke, I would carefully check the extension bushing.
just for entertainment purposes, this is a 375 housing next to a 350 housing. The 375 housing is upside down, so you can see the neat lettering on the bottom. As you can see the seal is the same.
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