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this how-to was made to explain how to swap the transfer gears of the first generation Stratus 2.0L into the A604/41TE 4 speed transmission

this is how to is valid for all third and fourth generation vans also equipped with the 4 speed atx

Chrysler has 3 sets of gears, the shortest one = higher final drive ratio are the only found in that particular Stratus swapping them will give you more acceleration less mpg

the middle ones are found in 90 or 95% of the Chrysler cars and vans no need to consider swapping them unless you have the 3.8L

the tallest one = lower final drive ratio are found in third and fourth gen van with the 3.8L engine swapping them = less acceleration maybe a little but better mpg

from my other car club
Pulled From The ASOG Archives!!! Special Thanks To ROBERT Original 3.5L Swap Guru!!!

The Final drive mod for the A604/41te tranny
Well, here it is tried and true. It really works! Given a set of new drive gears from the 99 Dodge stratus with the 2.0 motor (part# 4773275) this mod takes about and hour. The stock gears are a 47/49 tooth count, where as the stratus gears are a 46/50 count, better gear ratio for better acceleration.

First thing I did was jack the car up and remove the driver side tire and mud guard covering the outer part of the tranny. To remove the guard you will need a 10mm socket and at least 9 inch extension to reach it. There are two bolts holding that up. Once that is removed to will need the same 10mm socket to remove the bolts that secure the drive gears cover. Once removed you will need to use a chisel and slowly loosen the pan all the way around ensuring you do not bend the pan, or it might leak when you put it back on. Make sure to have a drip pan under there to catch the 1/2 quart worth of fluid that is going to run out on you.





Once removed this is what you will see. First remove the top gear by folding back the tab that is securing the 15mm bolts, each one has a little metal tab securing it, next remove the two 15mm bolts that hold the bolt retaining pin. Then once those are off the two rings will come off. Now you will need a 32mm socket to remove the main drive gear bolt. This is **** to remove. It took a breaker bar for me to get it off. One that bolt is off this gear should slide right off, if not then use a steering wheel puller to remove it. A GEAR REMOVAL TOOL WILL NOT FIT!! Also, DO NOT attempt to try to remove the gear by screwing to long bolts through the gear, all that will do is damage the bearing on the gear. Once that gear is removed to will need a 1 1/2 inch socket to remove the driven gear at the bottom. This one is **** to and you will need a steering wheel puller to get that one off. Once off be careful not to lose the little spacer ring that is on the back side of the gear. It may still be on the pinion shaft when you remove the gear. That is very important to have for reinstallation. Also inspect the bearing ring and cup that should still be pressed into the tranny. If they are loose make sure they are not worn and if they are a little loose tap them with a hammer carefully to make sure they are fully seated.



This is the first way I used to pull it and it bent the washers I used to hook the puller to, so you will need that steering wheel puller. Its a bar with a big screw in the center and two small ones on the outside, TRUST ME, GET ONE BEFORE YOU START! Now that the gears are off, reinstall the spacer ring and now press the bottom gear in. Make sure the splines are lined up before you start tapping it with the hammer .Only tap in the center on the smooth portion of the gear. Now it may not fully seat, but it will when the 1 1/2 inch bolt gets secured again. Make sure to torque it to manufacture specs. Now install the upper gear, reminder, make sure the smaller gear is installed on the upper shaft, the drive gear is smaller than the driven gear. One the upper gear is pressed on then secure the 32mm bolt to spec and then reinstall the retaining rings the same way they came off. Then reinstall the 15mm bolts to secure the retaining rings and remember to press the tab against the bolt heads again. Once done before reinstalling the cover remember to add that gasket of your choice, I used rtv 883 silicone. Allow 15 minutes to sit and while your waiting put the car in neutral and spin the drive wheel so you can see if there is any play in the gears, should not be. Then after time has elapsed then re-secure the cover and mud shield, tire and make sure your fluid level is ok. Take it out for a drive and listen to any suspicious noises. If you hear any abnormal, metal grinding, squeaking noises return immediately and disassemble and make sure your gears are still secure and the bearings are not locked up. Its very easy to do if you forgot that spacer, or did not torque your bolt correctly.

 

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Maybe swapping my gears to shorter ones will get rid of the transfer gear whine I have. Or it could just be an excuse to make the van mildly faster.
 

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So if we have the 3.8, the gears are already optimal for highway cruising?
 

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I am looking into changing my gears to optimize mileage but I would like to inject a note of caution here: The spacer rings he warns about not losing are the shims that adjust the bearing end play. The manual specifies a .001 end play for each which is pretty close tolerance. I would guess that the shims in your transmission are pretty close to right but pretty close is not an option here since the shim thickness goes from .183 to .058 which is one **** of an adjustment range to get a .001 end play. In other words, you will most likely be wrong and very likely be very wrong! I sugest that anyone contemplating this mod should obtain a shop manual and the proper tools before proceeding. On a positive note, I am looking for a set of 3.8 gears so if anyone does swap out a set , let me know. If anyone wants I can scan the manual and e-mail you the relevant pages.
 

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If I swap the gears from the Stratus into my GC will the increase in acceleration be noticeable? Will the rpm at highway speeds (70mph) increase?
 

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It will certainly help your acceleration, to what extent you will have to try it to find out.
Your RPM's will be higher the whole time you are rolling. Also your speedo will read faster than actually going. Not sure you will be able to reprogram the TCM enough to get the speedo correct since these transfer gears were never offered on your van.
 

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Why would the speedometer read higher? Correct me if I'm wrong, but I always thought the vehicle speed sensor was picking up axle rotations down stream of the final drive.
 

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It will certainly help your acceleration, to what extent you will have to try it to find out.
Your RPM's will be higher the whole time you are rolling. Also your speedo will read faster than actually going. Not sure you will be able to reprogram the TCM enough to get the speedo correct since these transfer gears were never offered on your van.
At around 70mph how much higher will the rpms be? Now at 70mph it is around 2000rpm.
 

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Why would the speedometer read higher? Correct me if I'm wrong, but I always thought the vehicle speed sensor was picking up axle rotations down stream of the final drive.
On the very early 41TE's there was a vehicle speed sensor on the right axle shaft housing. That went away about 92?.
Since then the vehicle speed reading is made out of: the speed of the output shaft sensor in the trans and calculation of what the transfer gear ratio is along with the diameter of the tires.
 

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On the very early 41TE's there was a vehicle speed sensor on the right axle shaft housing. That went away about 92?.
Since then the vehicle speed reading is made out of: the speed of the output shaft sensor in the trans and calculation of what the transfer gear ratio is along with the diameter of the tires.
Either way, changing the internal gearing will not affect the speedometer one way or another.
 

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Either way, changing the internal gearing will not affect the speedometer one way or another.
Can you explain to all of us how the speedo will be unaffected?:nut:
If the gears are changed and the output shaft is now spinning faster at say 60 MPH than it did with the old gears how can the speedo NOT be affected?:confused:
Think about this in the old school way, take 3:08 gears out of the diff of your 68 Dodge Charger and put 4:11's in. The driveshaft will spin faster and the speedo will read too fast.......
 

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At around 70mph how much higher will the rpms be? Now at 70mph it is around 2000rpm.
Hey fastgc, has your fuel economy increased with all the mods you've done, or has it went down? Never bothered to ask even though I've been following along with all your mods from beginning to now.

Pretty sure if you swap gears fuel economy will go down. But then again you're looking for performance and speed, so you're not that concerned with fuel economy. Got around to installing that shift kit yet?

You influence me to do some performance mods myself. I'll soon be on the hunt for the 3.8 throttle body, intake manifold and exhaust, should help in fuel economy. $100-$120 in gas per week is kinda getting ridiculous at this point.
 

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Either way, changing the internal gearing will not affect the speedometer one way or another.
What are you basing this statement on?
 

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Can you explain to all of us how the speedo will be unaffected?:nut:
If the gears are changed and the output shaft is now spinning faster at say 60 MPH than it did with the old gears how can the speedo NOT be affected?:confused:
Think about this in the old school way, take 3:08 gears out of the diff of your 68 Dodge Charger and put 4:11's in. The driveshaft will spin faster and the speedo will read too fast.......
For an old Dodge Charger (regardless of whether it is the 727 or the A904) the speedometer pickup is a mechanical gear run off the drive shaft, so in that case, changing the differential will have an affect on the speedo, on the 41TE it is my understanding that the speed sensor is down stream of the final drive.
 

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Well then you are understanding it wrong.
 

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Hey fastgc, has your fuel economy increased with all the mods you've done, or has it went down? Never bothered to ask even though I've been following along with all your mods from beginning to now.

Pretty sure if you swap gears fuel economy will go down. But then again you're looking for performance and speed, so you're not that concerned with fuel economy. Got around to installing that shift kit yet?

You influence me to do some performance mods myself. I'll soon be on the hunt for the 3.8 throttle body, intake manifold and exhaust, should help in fuel economy. $100-$120 in gas per week is kinda getting ridiculous at this point.
Some mods made the mpg go up and others made it go down. The cold air intake, exhaust, and larger throttle body increased mpg. After doing the cam the mpg reduced. I am not that much concerned with fuel economy. The shift kit hasn't been installed yet.

Get the 3.8 throttle body, intake manifold, and exhaust. For the exhaust, change the muffler to a super turbo (if you want it to be quiet) or something like a Magnaflow (if you don't mind the extra noise). The major restriction in the exhaust is the muffler. If you want to, you can also get a high flow cat also. These upgrades should get you better fuel economy.
 

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Some mods made the mpg go up and others made it go down. The cold air intake, exhaust, and larger throttle body increased mpg. After doing the cam the mpg reduced. I am not that much concerned with fuel economy. The shift kit hasn't been installed yet.

Get the 3.8 throttle body, intake manifold, and exhaust. For the exhaust, change the muffler to a super turbo (if you want it to be quiet) or something like a Magnaflow (if you don't mind the extra noise). The major restriction in the exhaust is the muffler. If you want to, you can also get a high flow cat also. These upgrades should get you better fuel economy.
Yea I like my exhausts quiet and not noisy. The turbo muffler will be the best way for me to go, and with the 3.8 exhaust fuel economy and acceleration will increase some.

I'm just waiting for the ever so slight flex pipe exhaust leak at idle to open up some more.. Gonna go to the junkyard later on and get everything for cheap there.

Question: are the cat converter the same or different for the 3.3/3.8? I'd assume they are different because the 3.8 has a bigger exhaust?


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Yea I like my exhausts quiet and not noisy. The turbo muffler will be the best way for me to go, and with the 3.8 exhaust fuel economy and acceleration will increase some.

I'm just waiting for the ever so slight flex pipe exhaust leak at idle to open up some more.. Gonna go to the junkyard later on and get everything for cheap there.

Question: are the cat converter the same or different for the 3.3/3.8? I'd assume they are different because the 3.8 has a bigger exhaust?


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The cat converters are the same. It says here that it is OE inlet and outlet size for both the 3.3 and the 3.8:

http://www.jegs.com/i/Magnaflow/642/93202/10002/-1?CAWELAID=1710872831&CAGPSPN=pla&catargetid=1784156849&cadevice=c&gclid=CI723LqLi74CFa5DMgodzXUAqQ

There are many high flow cats. I am using the Magnaflow one. It costs $67 from Amazon:

http://www.amazon.com/Magnaflow-94006-Universal-Catalytic-Converter/dp/B000COPBT4/ref=sr_1_1?s=automotive&ie=UTF8&qid=1398960025&sr=1-1&keywords=magnaflow+2.5+universal+cat
 

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Thanks. I'll be reusing the same CAT that I have on my van... Trying to keep costs low here lol.


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