a343f reverse fix (1 Viewer)

[Warpigg]

i have the common early 343f trans problem in reverse, where under load it slips. id like to fix this since i back up my steep driveway in winter. sometimes driving up isnt an option. i have read up on the fixes toyota did on the later years to fix this.

i dont plan to drop my trans mission to fix this, i live with it if i have to. i know the brake return spring is in the lowest valve body and should be easy to get to. im not sure where the low coast modulator is? since the spring for that is part of the toyota fix. along with the 3 o-rings that were updated.

so my ultimate question is what actually fixes the issue? the brake spring? or the modulator spring, or both? where are the o-rings located as well? could be a "while im in there" type thing.

 

[Warpigg]

i guess ill order the brake return spring and see what happens

 

[Hedgehopper88]

I'm curious what yo u come up with. My 94 does the same thing.

 

[brianh699]

Post #18 details the TSB issued by Toyota for the A343f
Transmission Lifetime?

I'm curious what yo u come up with. My 94 does the same thing.

Your 94 uses a different transmission.

 

[iptman]

i guess ill order the brake return spring and see what happens

Did you drain some ATF and see what color it is? If its dark or straight up black you probably burned up a reverse clutch disk. I had to swap transmissions to fix this in my 97. I havent bothered to open it up to prove out this theory though.

 

[Warpigg]

so after further research the 1st/reverse brake return spring is in the front of the clutch pack, not the valve body. the low coast modulator may be in the valve body but idk. im going to go with the transgo refresh kit and see where it gets me. the lack of information is abundant on the 343f unfortunately...

 

[flintknapper]

so after further research the 1st/reverse brake return spring is in the front of the clutch pack, not the valve body. the low coast modulator may be in the valve body but idk. im going to go with the transgo refresh kit and see where it gets me. the lack of information is abundant on the 343f unfortunately...

Low Coast Modulator should be found in the lower valve body.

 

[ccslider]

Mine has this same issue, only experienced it twice. Last time it happened I was forcing the truck to climb up a 2 ft ledge in reverse.

 

[Warpigg]

Low Coast Modulator should be found in the lower valve body.

I haven't been able to find the low coast modulator in any diagrams. Seen lots of compression springs in diagrams but none that say what they're for.

 

[bigredmachine]

I'm curious what yo u come up with. My 94 does the same thing.

93-94 has the a442 trans, 95-97 has a different trans

 

[Vudu77]

Warpigg, did the transgo work for the reverse slip issue? Mine just started and I'm looking for solutions. Many have been posted but no follow up saying which actually worked.

 

[flintknapper]

Mine has never done this (so far). I have a '97 with a build date of December 1996. Haven't ever looked at the transmission tag to check its serial number.

My vehicle doesn't see much hard use. But I have backed up a trailer with 3 round bales on it (about 1200 lbs. each) up a pretty steep incline. Used low range though...so maybe that made a difference.

 

[Warpigg]

The shift kit definitely improved my reverse and all around helped