Hi, I'm going to attempt to do my first transmission oil change on my 1998 grand caravan AWD 3.8 ltr, 160,000 miles. I don't think there is anything wrong with my tranny yet but doing it as a maintanence precaution. I've been doing my research on the internet and random people but get alot of conflicting advice. First of all, I have bought a felpro filter and gasket kit. The guy at the auto parts shop told me not to use any RTV sealant on the filter. He said just to press the filter snuggly around the tranny pan holes and then screw the bolts through the gasket because the holes in the gasket are smaller then the bolts. Is this good advice? Should I get the RTV sealant and add the 1/8 inch of bead to both sides of gasket? or just one one side? Also, Should I do a complete tranny oil change or just a partial? I just get scared of damaging the tranny while flushing the system. If I did choose to drain the system, how can I be sure to dissconnect the right hose for the old fluid to be pumped from? And how can I be sure not to run the tranny dry? Another thing I'm concerned about is the TCM firmware. I've read that I may have to flash the firmware at a dealership because the computer is used to the old fluid or something??? Another quick question, I seen at Walmart they had ATF +4 which I only need ATF+3 but they had a gallon of synthetic tranny fluid for cheaper then the ATF +4. Would the synthetic fluid be superior to the ATF+4?

No way for the powertrain module to know
you changed the fluid
Shouldn't need to worry about drive cycles
but the clutch packs may react different for
awhile as the friction coeficent will be different

If you use regular Dex/Merc v.s. +4 add black lubgard No way for the powertrain module to know you changed the fluid Shouldn't need to worry about drive cycles but the clutch packs may react different for awhile as the friction coeficent will be different If you use regular Dex/Merc v.s. +4 add black lubgard

Thanks alot pczapp:)

That's some great info. I'm sticking with ATF+4. Why would the tranny start slipping if I flushed the whole system vs. just changing pan oil??? I'm just gonna go ahead and change the pan oil out tomorrow. I'll let you know how it goes.

Thanks again Thanks alot pczapp:) That's some great info. I'm sticking with ATF+4. Why would the tranny start slipping if I flushed the whole system vs. just changing pan oil??? I'm just gonna go ahead and change the pan oil out tomorrow. I'll let you know how it goes. Thanks again

I made a living in the trans repair business for a few
years. 70% of my work was caravans & taurus

The caravan is a terrible transaxle
When you don't change fluid every 30,000 miles
on all vehicles your going to not make 100,000 miles
That is most of the reason for clutch waer from heat
That is the job of the fluid to remove heat.
As I said new fluid on a trans with more than 60,000
miles will cause slippage very easily. So I suggest
just drop the pan & be happy with about a 4 qt replacement
Then every year in May,BEFORE it gets hot do it again
Also if you use +4 use the red lubguard,only chemical
I ever found that does anything. Some asian transaxles
won't shift without it. I made a living in the trans repair business for a few years. 70% of my work was caravans & taurus The caravan is a terrible transaxle When you don't change fluid every 30,000 miles on all vehicles your going to not make 100,000 miles That is most of the reason for clutch waer from heat That is the job of the fluid to remove heat. As I said new fluid on a trans with more than 60,000 miles will cause slippage very easily. So I suggest just drop the pan & be happy with about a 4 qt replacement Then every year in May,BEFORE it gets hot do it again Also if you use +4 use the red lubguard,only chemical I ever found that does anything. Some asian transaxles won't shift without it.

I think I'm in trouble pczapp...

WHen I went to instal the clean pan back onto the tranny case, three of the bolts had been stripped from a previous job and they would not screw in tight. The good thing is that the 3 stripped bolts arn't next to each other so I'm hoping the 2 bolts next to each of the stripped bolts can hold the pan tight enough to prevent a leak. Although, 2 of the 3 stripped bolts are on a corner.

I filled up the pan with 4 qts of atf+4 and watched for leaks and there were no leaks while I let the engine idle for 2 minutes. If there is a leak, I'll just get another filter and RTV sealant and hopefully that will stop it. I think I'm in trouble pczapp... WHen I went to instal the clean pan back onto the tranny case, three of the bolts had been stripped from a previous job and they would not screw in tight. The good thing is that the 3 stripped bolts arn't next to each other so I'm hoping the 2 bolts next to each of the stripped bolts can hold the pan tight enough to prevent a leak. Although, 2 of the 3 stripped bolts are on a corner. I filled up the pan with 4 qts of atf+4 and watched for leaks and there were no leaks while I let the engine idle for 2 minutes. If there is a leak, I'll just get another filter and RTV sealant and hopefully that will stop it.

Should have told you to always use Anti-Seize on bolts
with anything especially aluminium
Drill & Tap them to the next metric size
Why would you need another filter? Should have told you to always use Anti-Seize on bolts with anything especially aluminium Drill & Tap them to the next metric size Why would you need another filter?