833 4 speed gearbox

by **denis iwaszczuk** » 19 Mar 2001 8:17

hi could any one help me i own a 1970 challenger 383 4speed i live in adelaide south australia and need a hand on some info on rebulding the box tech sheet what ever your help would great. thanks denis

by **dave-r** » 19 Mar 2001 11:19

That is a big section of the workshop manual mate.
I think you would be better off getting a re-print from Year One.

by **denis** » 26 Mar 2001 8:43

thanks dave but i'll be wating about a month was just after some tips on assemebly.

by **Duane** » 23 Aug 2001 16:42

Can synthetic gear oil damage the seals in an A-833? I bought my trans from a Mopar salvage yard (I replaced a 3-speed A-230 with it) and it shifted fine, in all gears, with minimal noise (to my ears, anyway). If there were any leaks, they were not really very noticable. The first winter I had the 4-speed in the car, I noticed it bacame hard to shift. My mechanic suggested I go to thinner synthetic oil, which did make it a bit easier to shift in cold weather. However, it almost immediately started leaking out. I think the front seal and reverse lever seal are the primary areas. I have heard conflicting theories - one that the synthetic oil is the cause, one that it should have no effect. Of course the seals in the trans were old to begin with. I am running regular gear oil in the car now but I have to keep a drip pan under it. I plan to get the work done to replace the seals soon (I have them) but this is beyond my ability and schedule right now.

by **dave-r** » 23 Aug 2001 21:18

People I know with these manual shifters use Auto trans fluid in them not gearbox oil. I have heard several people from several different sources saying use auto fluid. Sounds funny I know but it seems to like it and feels much better to shift.

The thinner oil will leak past worn oil seals easier. Sounds like you need new seals.

by **LITEMUP** » 10 Dec 2004 17:44

ok, my dad is putting a 4 speed up to a 340 in our purple car. he said he got the bearing that they told him to off of moparts.com i think it was. he said it went in real easy and its a bit sloppy. i have not seen this problem first hand, so i can't give much info. the bearing is tapered with a steep ride on one side. does anyone know the problem or should he just hammer it in more...
http://www.moparts.com/Tech/Archive/clutch/1.html
this is the link he sent me. he said they told him and he got the bearing on the left.

by **dave-r** » 10 Dec 2004 19:23

Oh that is the pilot bushing that the input shaft of the gearbox fits into on the flywheel. Without it the bearing on the front of the gearbox will fail (a weak area anyway on these transmissions).

Now if I remember right there are two sizes you can get depending on if the end of the crank has been finish cut to the correct size or not.

You see all cranks came with a hole in the end but when intended for use with a manual trans the hole was machined out to an exact size for the bearing.

However you can now get a bearing that fits in the non-machined hole to save you the hassle of getting the machining done when swapping from an auto to a manual trans.

Now if you bought the smaller bearing intended for the un-machined hole but you had a crank that has been machined for a standard bushing it would be a very loose fit.

I suggest you get your digital caliper out and measure the outside diameter of the bearing and the inside diameter of the hole. Only if they are the same size should you start hitting it in harder!

Don't forget to measure and cut the input shaft to the correct length too if needed.

by **Christer** » 11 Dec 2004 16:22

I found a sentence in Dave Adkins book that might be of intrest: "The tip of the input shaft, which rides in the pilot bushing in the rear of the crankshaft, is the same size on both the 18-spline and 23-spline transmissions." Not much help, I guess. Good luck.

by **Christer** » 11 Dec 2004 17:29

In the Mopar chassis book, I found a section about automatic to manual transmission conversions :

"There are a couple of problems that must be checked out before starting. The cast crank engine can cause a severe vibration problem if it´s external balance is omitted. Also the crank should be checked to be sure that it has the provision to allow a pilot bushing to be installed. Not all automatic crankshafts have the flange mashined for this bushing and the nose of the transmission."

by **dave-r** » 11 Dec 2004 17:59

That is the point I was making. Some cranks are already machined for the pilot bushing. All 4-speed cars had this of course but also some automatics had a machined crank.

So if you use a bushing designed for the un-machined hole in one of these cranks it is going to be loose!

Also on the un-machined cranks you have to shorten the input shaft because the hole is not deep enough.

by **transman** » 14 Dec 2004 21:23

The use of ATF in an A833 trans. is OK. Some of the early ones came with ATF in them from the factory. Remember though, ATF being thinner can cause leakage problems on seals and gaskets that might be questionable.
I asked a standard transmission mechanic about cutting down on the length of the snout on the input shaft. He said that this was not the way to go. He pointed out that the snout is a support for the transmission, and if it is removed, other than the input bearing, the input shaft is not supported, except for the input bearing in the transmission.
The pilot bushing/bearing is the same for all V8 engines from what information I've been able to find.
If you have an engine that came with an automatic, and you want to change over to a standard transmission, spend the money and have the crank machined to accept the pilot bushing/bearing, (in other words, convert it to a standard crank). If I was going to convert my Challenger over to a standard transmission, I'd make damn sure that the enginge shop knew how to do this properly. Doing it in any other manner might save you some time and money in the short run, but in the long run could cost you considerably more.

Just my observations and Holiday Good wishes to all.

Transman