oops? 4 speed

[scottb]

ummmmmmmm....... getting closer to being road ready.......

Changing the fluid in the gear box, pulled the VSS thingy to fill it. Sensor and gear successfully removed. But, is there anything below the gear to hold it in place? I thought i heard something go "tink" when I pulled everything. Just need some assurance for some peace of mind: as in I don't want to pull the gearbox yet.

Thanks,
Scott

[TopNotch]

If the gear is still there, you should be OK. I don't recall anything else beyond the gear. I've done trans fluid on 2 manuals, but both were 5-speed Isuzu's.

[Fierofool]

I've done fluid on all 3 manuals, but I don't recall having looked in while the trans was drained, but from the impression I've gotten from others, there is a small ledge down there.  I'd have to think that is the case, else the ring gear that drives the speedo would pull the plastic gear off the shaft when you go into reverse. 

Did you drop the retainer tab that holds the VSS? 

[f85gtron]

i can verify that there is indeed a ledge directly under the vss and gear.  it will support the gear, but only up until the moment you reach for the gear (that fell off the vss that you just man-handled out of it's home), at which point it jumps off and remains just at the edge of your grasp, taunting you, moving further away with every try.....don't ask me how i know.....
Ron

[scottb]

OK, thats good news. I didnt measure anything, it just looked to me like there should something under the gear to hold it in place.

Can anyone verify what the capacity is? I keep finding different specs. Everything on the internet is true, right?

Thanks, Scott

[Fierofool]

It's about 2.7 quarts.  I'd strongly recommend that you pull the gear off the VSS to avoid dropping it into the trans as you insert and remove the VSS while you check for the correct level.  I'd also recommend going to AutoZone and getting some Penzoil Manual Transmission Fluid.  Same as GM Synchromesh Fluid. 

[scottb]

you mean gear oil isnt right?? I know, i picked up synchromesh last night.

[f85gtron]

i used motor oil in my 4speed.  was i not supposed to?  that's what the manual called for....

[Fierofool]

Early on, 5 w 30 motor oil was the recommended lubricant, both for the 4-speed Muncie and the 5-speed Isuzu.  At some point, and I think that was in 86 that they changed to recommending Synchromesh.  I don't know if it came about with the introduction of the Getrag, but it did include the Isuzu, which was identical to the 85 Isuzu. 

Lots of people, including myself, have changed the early 4 and 5 speeds to Synchromesh without any problems, and usually with improvement of shifting. 

I don't know if the change from 5 w 30 was due to GM wanting to make a few extra bucks by providing something claimed to be necessary for the transmissions at more than twice the cost of readily available motor oil, or because there was something different about the later transmissions.  Whatever the case, most of us have found, or think we've found, that the transmission shifting is smoother with Synchromesh.

[TopNotch]

I heard that it was something to do with the brass synchronizer rings in the transmission being corroded by detergents in regular motor oil.

[f85gtron]

dough!