Redog

OK I found out today that the tranny hooked up to the motor is a TH 400 and not a TH 350.

The good part is that it's a 400, the bad news is that I bought the driveshaft with the 350 yoke (smacks head, althought my mech wants to do that for me).

There is no speedo hookup Is it the wheel one, and how do I hook that up to an 1985 Delta?

Oldsguy

If it is the wheel type one you should see a cable coming out of the front driver's side backing plate but I don't think they still did that in '85. I am working from memory but I think the cable housing attaches on the driver side just above the pan about midway. If you do have the type that required the cable to the wheel you would have to find that whole assembly from a donor car. It would require the spindle with the hole in it and I don't know if the older style would fit on your '85 Delta or not. I bet it could be done but would probably not be easy. Don't forget the bearing dust cap with the cable termination on the inside of it, it sort of looks like a little nut with a square hole in the center that is brazed on the inside of the cap.

joe_padavano

The wheel-driven speedo drive will not adapt to a 77-85 B-body. Your trans may have a plug in the opening used for the speedo cable adapter, or it may have solid metal. If you have the plug, it's possible to knock the plug out, push a speedo drive gear onto the output shaft, and install the speedo cable adapter from another trans. If your case is not machined, you need a different trans.

Oldsguy

Thanks for that clarification Joe, I was doubtful that it work.

88 coupe

Only the output shaft and/or housing.

Norm

Olds64

Couldn't he take the output shaft and housing off and have a machinist modify it? Then again, parts are so common for a TH 400 it would probably be cheaper to just find what he needed in a salvage yard.

Good luck!

2blu442

This thread got me to thinking, and I went out to the trannie grave yard to look at TH400's. I looked at 5 of them with the speedometer cable and they all attach in the main trannie body, not the tail shaft. I also have some of the wheel cable TH400's and looked at one of them. Comparing the two I think Joe's right, that Redog won't be able to use that trannie with any kind of conventional speedometer cable.

88 coupe

If the tailshafts/housings do not interchange, Joe is right.

Norm

joe_padavano

The speedo cable fitting bolts into the main trans case, not the output housing. You can unbolt the tail housing, press a speedo drive cable onto the existing output shaft, and reinstall the housing. The problem is the opening in the trans case. If the trans has the hole machined and a plug pressed in, it's easy to retrofit the speedo cable. If the case is not machined, it's a lot of work.

Oldsguy

I am going to have to address this issue in my application. The TH400 came from a '69 Delta 88 that used the wheel speedo so there is a hole in the side of the transmission case for that. However the transmission is now in a '46 Olds and I am going to have to find a way to drive the speedo, or go without it and cover the hole so I don't loose all the fluid!

Glad this post came up because I didn't think about that earlier..........there is always something left undone.

joe_padavano

Dan,

Not sure I completely follow your question. If the trans has the opening for a speedo cable fitting, just get one and bolt it in. If the trans has a plug in the hole, knock it out and install the drive gear as I noted above. If there is no opening, you're SOL.

Oldsguy

I doubt the front hub on the '46 has a hole in the spindle to accomodate the cable, and then, I don't have the cable assembly either. Going to have to think this one out some.

Redog

I'm in luck, there is a "knock-out" plug on the side of the tranny and I bought the housing and gears for the speedo, I just don't have the cash to get it fixed right now

J-(Chicago)

Hahaha, Joe P is so helpful.
He could probably whoop Chuck Norris and Rain man at the same time.

I hope someday he writes a few books on all this stuff.

Oldsguy

OK, I realized my error in reasoning and understand Joe's confusion (probably you all think I am an idiot ). I think I will be in the same situation as redog and will be inspecting my transmission housing for a knockout area soon. Redog, where did you go for the parts to convert yours?