I got the 02 cavalier f23 to use with the 3800sc. I read a lot about the gearing not being great for this swap so I bought the 09 cobalt trans to swap the final gear into the cavalier trans. The cobalt final gear is smaller so it's not meshing with the other gear the same. My question is what else do I need out of the cobalt trans to swap into the cavalier trans? Thanks in advance
You have to install the bellhousing from the '02 Cavalier transmission on the Cobalt transmission.
The final *ratio* comes from the pinion gear on the output shaft and the ring gear on the differential. The '02 Cavalier trans has a 3.94 final ratio. The XFE Cobalt trans has a 3.63 final ratio. As you found, you can not use the ring gear from the 3.63 with the pinion from the 3.94.
Did your transmission come from the Cobalt XFE model? That trans has the 3.63 final drive.
Also, the Cobalt input shaft is longer than the Cavalier input shaft, so you'll have to do some work on the input shaft so that it doesn't interfere with the 3800 crank snout.
I have the 3.63 ratio in my F23 and I can tell you it is WAY better for the 3800 than the standard cavalier gearing. I notice a big difference. (I had a previous car with an F23 with cavalier gearing)
It would be awesome if someone could document the gearing swap for others to use as a template. I bought mine already swapped, so I have no real info to offer unfortunately.
[This message has been edited by cam-a-lot (edited 10-04-2022).]
Yes, I bought the trans from the xfe cobalt. It looks like the pinion gear (or whatever the gear is that turns the ring gear) is the same on both transmissions. If that's true, what determines how close or far the gears are? Would the bearing races on the case be different to move the gearing?
Yes, I bought the trans from the xfe cobalt. It looks like the pinion gear (or whatever the gear is that turns the ring gear) is the same on both transmissions. If that's true, what determines how close or far the gears are? Would the bearing races on the case be different to move the gearing?
the bellhousing can bee swapped between transmissions, because the bellhousing also carries one of the differential bearings, they must be in the same place on each transmission, which means both the pinion and the final drive need to have changed.
as Will said, you either need to swap the bellhousing, or transfer the entire gearset into the cavalier case. My car has a 3.63 gearset with a cavalier bellhousing.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
me personally, I would keep all the gearsets together, I'm unsure if they're the same outside of the length difference.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
Yes, I bought the trans from the xfe cobalt. It looks like the pinion gear (or whatever the gear is that turns the ring gear) is the same on both transmissions. If that's true, what determines how close or far the gears are? Would the bearing races on the case be different to move the gearing?
They might have the same tooth count, but they are NOT the same gear. The diameter MUST be different in order for there to be a different ratio on the same shaft center separation.
quote
Originally posted by ericjon262:
the bellhousing can bee swapped between transmissions, because the bellhousing also carries one of the differential bearings, they must be in the same place on each transmission, which means both the pinion and the final drive need to have changed.
as Will said, you either need to swap the bellhousing, or transfer the entire gearset into the cavalier case. My car has a 3.63 gearset with a cavalier bellhousing.
The rest of the ratios are the same, except for the Saturn Vue transmission (5th: 0.81). The Cavalier bellhousing and input shaft *should* be able to stay together on the XFE transmission without causing any problems.
I was thinking it would probably be wise to keep them together so that any wear that has occurred at the tooth interfaces will be uniform between the teeth, and maintained in approximately the same places. putting different gears in probably won't be a problem, but stacked tolerances, manufacturing variations, changes in production working standards can all make things that should work, not. the manufacturer was never expecting us to do this to these transmissions, so they probably didn't give any thought to production changes up to 7-8 years apart, or even small engineering changes, we don't have part number breakdowns for each shaft and gear to see that they're even the same PN.
Not saying it won't work, just saying that the OP has two working transmission gearsets, and mixing them has some potential to create two non working gearsets.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
I was thinking it would probably be wise to keep them together so that any wear that has occurred at the tooth interfaces will be uniform between the teeth, and maintained in approximately the same places. putting different gears in probably won't be a problem, but stacked tolerances, manufacturing variations, changes in production working standards can all make things that should work, not. the manufacturer was never expecting us to do this to these transmissions, so they probably didn't give any thought to production changes up to 7-8 years apart, or even small engineering changes, we don't have part number breakdowns for each shaft and gear to see that they're even the same PN.
Not saying it won't work, just saying that the OP has two working transmission gearsets, and mixing them has some potential to create two non working gearsets.
I haven't counted in an F23 yet, but continuous mesh gears should have mutually prime tooth counts, meaning that every tooth on each gear touches every tooth on the other gear. This makes wear patterns a non-issue. I get what you're saying as a possibility, but concerns of an incompatible design are relatively easy to check for via a trial assembly.
There are two potential upsides to keeping the input shaft and bellhousing together: No further input shaft modifications required to use the transmission and the Ecotec transmission can be re-sold with a 3.94 FD, which was never offered from the factory and may be appealing to Cobalt (or even G5!) enthusiasts.
[This message has been edited by Will (edited 10-14-2022).]
I'll be sure to take pics of everything. Right now, I have the gears out of the cobalt trans and going to start on the cavalier trans to compare everything and see what I can use from which trans. I started comparing part numbers for bearings on both transmissions. I'll take a pic of the list I made when I get home
I haven't counted in an F23 yet, but continuous mesh gears should have mutually prime tooth counts, meaning that every tooth on each gear touches every tooth on the other gear. This makes wear patterns a non-issue. I get what you're saying as a possibility, but concerns of an incompatible design are relatively easy to check for via a trial assembly.
There are two potential upsides to keeping the input shaft and bellhousing together: No further input shaft modifications required to use the transmission and the Ecotect transmission can be re-sold with a 3.94 FD, which was never offered from the factory and may be appealing to Cobalt (or even G5!) enthusiasts.
Right, but two different gearsets with unknown service history and unknown usage characteristics will have have different amounts of wear and tear. Do I think the gears will fail if he does that? probably not. They were just the thoughts I had on swapping the shafts.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
Ok, I think I'm going to use the cavalier case with the cobalt gears but keeping the cavalier input shaft. Once I get both sets of gears out, I'll compare the shafts and gears side by side to be sure this is possible. I'll put all new bearings In after comparing part numbers between the transmissions. It'll take me a bit to do this financially but I'll take pics along the way for a complete write up.
Right, but two different gearsets with unknown service history and unknown usage characteristics will have have different amounts of wear and tear. Do I think the gears will fail if he does that? probably not. They were just the thoughts I had on swapping the shafts.
If you're worried about that, pulling the clusters out gives better accessibility to inspect every tooth
