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| F23 final gear swap question (Page 2/2) |
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cam-a-lot
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OCT 08, 08:09 AM
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Mike, can you please document and take photos as a build thread as you do the gear swap, so others can benefit? Would be great.
Thx
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Will
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OCT 11, 03:52 PM
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| quote | Originally posted by Miked0002:
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? |
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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.
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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.
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ericjon262
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OCT 11, 07:43 PM
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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.
No pushrod 60V6 Fiero has been faster according to the 1/4 mile list.
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Will
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OCT 12, 05:10 PM
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| quote | Originally posted by ericjon262:
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.
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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).]
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Miked0002
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OCT 12, 05:14 PM
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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
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ericjon262
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OCT 13, 02:03 PM
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| quote | Originally posted by Will:
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.
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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.
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"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.
No pushrod 60V6 Fiero has been faster according to the 1/4 mile list.
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Miked0002
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OCT 14, 02:41 PM
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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.
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Will
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OCT 18, 08:57 AM
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| quote | Originally posted by ericjon262:
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.
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If you're worried about that, pulling the clusters out gives better accessibility to inspect every tooth 
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