bwh69s

I have a 69 Cutlass that I'm swapping out the 350 motor and TH 350 tranny with a 455 and TH 400. I picked up a rebuilt TH 400 that came out of a 67 Delta 88. Unfortunately for me, I didn't notice until after I bought the tranny that the case has no port for the speedometer grive gear that the speedometer cable connects to. Has anyone come across this before, maybe the this tranny came from a different application like a truck or something? Do I have any options other than buying another TH 400?

don71

The car that transmission came from had the speedometer driven from the front wheel. Finding another transmission is really your only choice.

67 D88Custom

Also, if it actually came out of a '67 Delta 88 it would be a long tail shaft (9 inch) TH400 and I would think you would need a short tail shaft (4 inch) version to fit your A Body Cutlass correctly relative to the crossmember mount and driveshaft length. In addition, if it was not converted as part of the rebuild, a TH400 out of '67 full size Olds would typically be a variable pitch (aka switch pitch) version that was used only in '65-'67 model years. Will require some tricky additional wiring to operate correctly. Combined with the lack of a speedo drive, you may want to consider acquiring a different model year TH400 with the short shaft to save yourself a lot of extra work.

Frisbee_k9

You could Get a GPS speedometer. The guy that built my 422 did that. Same reason no port.

67 D88Custom

Good point about the GPS speedo option, Guy. I forget about that modern stuff.

Frisbee_k9

I never heard of it until I was looking at this car. The builder said the trans th 400 didn’t have the set up for the speedo so he put in Speed Hut speedo and quad temp,oil, elect and gas.

bwh69s

Yeah, I thought of the GPS route, but don't want to make that my primary speed gauge if I can avoid it.

bwh69s

don71, is there a source for the front wheel speedo setup?

bwh69s

67 D88Custom, Yes my 400 does have the long shaft. But, It appears to have been converted during rebuild as there are no electrical connections other than the Kickdown switch.

don71

As far as I know, you can't retrofit a front drive assembly from a big B/C car to the smaller Cutlass A body chassis. I really feel like if you want a proper speedo, you'll have to find another transmission. And considering you have a long shaft, you'll be out time and frustration trying to make what you have function properly in my opinion.

67 D88Custom

I fully agree with Don71, trying to fit a wheel drive speedo assembly to the car would be a nightmare far greater than finding a more compatible transmission. First off, some of the parts are unique (such as the speedo cable), are not made or reproduced, and practically impossible to find even used. The cable itself, even if you found one, routes through a hole specially drilled through the hub to connect with a unique cap over the outer wheel bearing - all things which, as far as I know, are not present on your '69 and would not retrofit well if at all. Further, even if you found all the parts and somehow made them fit, I am doubtful the setup would be compatible with the factory '69 speedo head on an A Body which I believe was originally transmission driven.

I don't mean to rain on your parade - just questioning whether it is worth the time/money/effort vs. finding a different transmission. Lots of TH400s out there compared to front wheel driven speedo parts.

Dave

joe_padavano

All 1965-70 Olds full size cars drove the speedo off the left front wheel. The trans does not have a provision for a speedo drive gear. For the most part, the cases are not even machined for the speedo gear adapter, so without disassembling the trans and putting the case on a milling machine, it is impossible to convert them to have a speedo drive. SOME of these cases do have the hole machined and have a cup plug pressed into the hole. In those cases, you CAN knock out the plug and install a TH400 speedo gear adapter. Of course, you also need to pull the tailhousing off and install a speedo drive gear on the output shaft, and that output shaft will still be a long tail version, so at the end of the day, just get a correct short tail TH400.

matt69olds

Where is the OP located? I have a couple BOP cases with speedo provisions. Maybe we could work out a trade?

Greg Rogers

I took a T400 out of a Big Buick( '66-67?) back in the day. It didn't have a speedo gear, but I took it apart and looked at it and it looked like ( as Joe said ) that a gear could be slid on the output shaft and the plug could have been removed and the hub installed. Back in the day I used to buy, repair and sell old cars. I have put long transmissions in GM cars where shorts had came out. I had the driveshafts shortened. Maybe it messed up drivetrain angle or something, I dunno, but it worked and drove OK. Course back then they were 10 year old rusty beaters. Now these cars are 50 years old and probably worth fixing properly, Unless it really is a beater I also would recommend getting the proper trans. Oh, is the th350 Ok? I put a stock 455 in front of a T350 in a 73 Omega and ran the **** out of it- never failed for me after 4-5 years until car was totaled by next owner.