Saturn S-Series 5th Gear Swap

[cfg83]

thriftee -

Originally Posted by thriftee

Sorry for digging up the old thread, and thanks for posting it in the first place...

No problem, it's a complement.

So, if you had to do it over, would you:

1. Leave it alone
2. Use the 5th from a 97- SOHC so the stretch from 4th to 5th wasn't so big
3. do it with the 5th from a 98+ SOHC as done
4. use a 97- SOHC complete trans
5. use a 98+ SOHC complete trans

??????

I'm thinking of doing this if I get an DOHC SC2, which it seems might be a better car and motor overall than the SOHC SC2 model, but would like the economy of the SOHC or better on the highway

I would do #3 over again. Second to that I would consider #5, but I would need to crunch the numbers first at a gear/tire ratio calculator like this one :

Fatboy Raceworks » Graphical Transmission Gear Ratio Calculator

The quote you are referring to was in response to jasonm changing his *final* gear ratio. That's like changing the size of your tires because the final gear ratio is in play in all shift positions, just like the tires.

CarloSW2

[thriftee]

Originally Posted by cfg83

thriftee -



No problem, it's a complement.



I would do #3 over again. Second to that I would consider #5, but I would need to crunch the numbers first at a gear/tire ratio calculator like this one :


The quote you are referring to was in response to jasonm changing his *final* gear ratio. That's like changing the size of your tires because the final gear ratio is in play in all shift positions, just like the tires.

CarloSW2

Yes, I think those are the best two options as well. I'll have to ask my mechanic how much effort it would be to swap the whole thing, as I imagine that would be the deciding factor.

When you are in local traffic just lumbering along not trying to accelerate, at say 25 to 30 mph, what gear do you use and at what mph or rpm do you shift to 5th if you aren't trying to accelerate fast and its flat land?

[cfg83]

thriftee -

Originally Posted by thriftee

Yes, I think those are the best two options as well. I'll have to ask my mechanic how much effort it would be to swap the whole thing, as I imagine that would be the deciding factor.

When you are in local traffic just lumbering along not trying to accelerate, at say 25 to 30 mph, what gear do you use and at what mph or rpm do you shift to 5th if you aren't trying to accelerate fast and its flat land?

On the flat in steady state driving I can get into 5th at 20+ MPH. I don't look at the RPM in this situation. At 20 MPH I am right on the lug-line so I can only accelerate ever so slowly. 25 MPH is much easier.

The *only* thing I miss about my old 5th gear is that I could go into 5th at 15 MPH. I only really notice this on the freeway in traffic jams. If you don't have LA traffic congestion where you are, then no worries.

CarloSW2

[pete c]

Interesting thread.

I am the new owner of a '97 SW2 5 spd. Can't believe that it is so easy to do a 5th gear swap! I don't even have the car home yet and I am already searching for a junk SW1 tranny for it's 5th cog.

[thriftee]

Not easy to find unless you want to pay $250 for a whole trans, unless you are capable of pulling a trans yourself and your time is free

[cfg83]

thriftee -

Originally Posted by thriftee

Not easy to find unless you want to pay $250 for a whole trans, unless you are capable of pulling a trans yourself and your time is free

It's easy to open the tranny and get at the 5th gearset, but opening the tranny and not putting it back together ruins/rusts the rest of the gears unless you close it and refill it with ATF oil (I think).

Are you saying that (most?) salvage yards will say whole tranny or nothing?

CarloSW2

[pete c]

I'm sure that is what he's saying. A boneyard isn't gonna sell the gears out of a perfectly good tranny for less than the tranny's worth.

Another source might be someone with an S*1 that wants to just go fast. You could swap 5ths.

What are the odds of finding a tranny that is bad, but still has a good 5th gear?

I could see this being the case in the event of a wreck that caused case damage.

[cfg83]

Hello -

Someone did a write-up on same at saturnfans.com :

How-To: 5th gear swap with pictures. - SaturnFans Forums

CarloSW2

[itjstagame]

Carlos, Just to ask, maybe it's obvious, but did you use the synchros from the donor transmission too? I haven't opened anything up yet but see synchros selling separately on ebay for some reason and wasn't sure where they fit in to the swap.

Also, in one of the writes ups I saw mentioned about pulling the bearings or using new bearings, where do these fit in to the picture?

I just want to make sure that all I need are the gears themselves and a new gasket (and locktite and tranny fluid) or anything else like new bearings or bearing grease too.


Oh and last one, but to include, what tranny fluid did you end up using? From what I've read I've seen Dextron III ATF suggested, but still haven't confirmed what our cars had originally or if a generic ATF would work instead.

[cfg83]

itjstagame -

Originally Posted by itjstagame

Carlos, Just to ask, maybe it's obvious, but did you use the synchros from the donor transmission too? I haven't opened anything up yet but see synchros selling separately on ebay for some reason and wasn't sure where they fit in to the swap.

Also, in one of the writes ups I saw mentioned about pulling the bearings or using new bearings, where do these fit in to the picture?

I just want to make sure that all I need are the gears themselves and a new gasket (and locktite and tranny fluid) or anything else like new bearings or bearing grease too.


Oh and last one, but to include, what tranny fluid did you end up using? From what I've read I've seen Dextron III ATF suggested, but still haven't confirmed what our cars had originally or if a generic ATF would work instead.

There was no donor tranny. I bought both MP2 gears new from the Saturn Service department. I also bought a Saturn tranny gasket kit from same. Along with the gaskets the kit included some snap rings and a tiny transmission fluid cone filter. The idea was that I wanted my mechanic to have everything he needed to get the job done. That is overkill for you.

The only thing you absolutely need are the two gears. When you remove those gears you will have to undo a few other parts (like the snap rings?!?!?).

The key to the Saturn gear swap is that you don't have to drop the tranny. Remove the front driver tire and the 5th gear tranny cover is sitting there just *begging* to be opened.

I would also explore saturnfans.com for write-ups on Saturn tranny assembly/disassembly. That will lead you to other websites like differentracing that are dedicated to Saturn S-Series stuff. This is the *full* transaxle disassembly, so you can see more of the guts :

Disassembling the Saturn Manual Transaxle

I can't remember the tranny fluid but it was ATF.

CarloSW2