QuestionI have a TH425 transmission (mostly used in FWD Toronado's
and Eldo's). Mine is in a 1974 GMC Motorhome.
Since this vehicle has had MANY unknowledgeable hands messing with it, I have no clue whether I have the correct transmission dipstick or not and would like to know the dipstick length from the insertion stop to the bottom tip and distances from bottom tip to full and add marks.
AnswerI'm definitely not a TH 425 trans guru by any means, but I have found a couple shops online that sell rebuild kits and misc. parts for your trans. They don't list the dipstick specifically for this trans, but I'd think that if they can get all the other hard parts for one, they'd be able to source you a good dipstick. I've found the TH425 was used from 1966 to 1978 in the El Dorado, Toronado, Deville, and Fleetwoods.
As far as the dimensions go, I'd say that would be a crapshoot on the actual length of your particular dipstick. In other words, I don't even know if the most knowledgeable person in this area could rattle off the actual length of it.
In my opinion, if you're in doubt about whether or not the one you have is the correct dipstick, it would be best to just replace it. Maybe even a local junkyard would be of assistance to you. :)
http://www.transmissionpartsusa.com
http://www.cobratransmission.com
