A343F reverse noise (1 Viewer)

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So is this a destructive type of issue? What I mean is if I just wait a few seconds after I shift into reverse for the fluid to make its way through the passages correctly is that good enough or is there going to be damage if the updates aren't installed?

Kyon

Kyon,
Good question. AFAIK, there have been no significant number of reports of any transmission damage or failures on the 80-Series A343F trannies; '97, '96, or '95. We don't know how many had the repairs in those TSBs done under the original vehicle warranty.

I have a '97 and I have had (2 occasions) the noise in reverse. Stop, pull it out of reverse, back into reverse, and all is well. Kinda scary though.

As for the poster saying he puts the transfer case in N to "fix" the problem... well, that has nothing to do with it. The issue is in the transmission, not the transfer.

-B-
 
For me it became more and more of a problem as I added more weight to the truck and asked it to do more off road. It was happening more often and more severely as time passed. I'm not one to wait for a complete failure so I got on it as soon as time and funds allowed. I think the ODO was in the 175k range when the tranny was swapped out.
 
I took a look again and cannot find a TSB for the added check ball, at least not in the list here on 'mud. I would like to see what it entails and the part number for the check ball, even though I have no noise shifting out of reverse.

Looking again at the serial #s I guess mine only needs the new o-rings but that is way not worth the work I think. If there is a TSB for shifting out of reverse noise and it's only a check ball that can be installed by pulling the pan and valve body I might try it.
 
Here is the TSB for the reverse to P/N "chatter". This is the "missing balls" TSB that C-Dan likes to gloat about.

-B-
TSB-1.jpg
TSB-2.jpg
 
brian894x4 and landtank,
I replaced my trans a 97 with one from a 96, (this after loosing all drive in my 97 trans well my new to me 96 trans has the the reverse shudder, I changed the trans fluid out for a fluid that allison uses in there trannies, this changeover has minimized the noise and lack of drive substantially contact me and I can give some info on the fluid.

Colin
 
Colin,

If you have a solution then post it.
-B-
 
I have a parts list...
Send me your e-mail addy and I will forward these numbers and hopefully the pictures will follow.


B3 Brake return spring assembly and low coast modulator compression spring.
A340E 96JR-25596
A340F 96JR-46671
A343F 96JE-06161

"O"-Rings
A340E 97AR-27196
A340F 97AR-27976
A343F 97AE-07106

Old part # New Part # Part Name
35068-30011 35068-50010 Spring sub ass,1st&reverse brake return
90501-08088 90501-08169 Spring Compression for low cast modulator valve
90301-99193 90301-99084 O-ring for outer brake piston
90301-57188 90301-56007 O-ring for inner brake piston
90301-68191 90301-67005 O-ring for inner brake reactive sleeve

Looks like VIN # 04351-60090

Tacomas & 4-Runners are included as well

Thanks to Mr T for giving me the A442 bus tranny...
 
having the same issue with my tranny. i first noticed something was up when i was on incline in Drive and i would roll back. the same thing in Reverse as well (roll forward). i don't know if this is related or not. is it? i just changed my tranny fluid and notice the noise for the first time when i was in reverse and trying to climb. i put in low and had no problem but this was well after the 5 second L8shift was talking about.
 
having the same issue with my tranny. i first noticed something was up when i was on incline in Drive and i would roll back. the same thing in Reverse as well (roll forward). i don't know if this is related or not. is it? i just changed my tranny fluid and notice the noise for the first time when i was in reverse and trying to climb. i put in low and had no problem but this was well after the 5 second L8shift was talking about.

Len, or others, what has been done to correct the problem? I have a 96 LX450 having difficulty going up grade in reverse. 4L works fine. Thanks,
Jon
 
I just wait till reverse engages and it doesn't make the noise.. Not real helpful but it is what i do.
 
Thanks Len, Yours sounds a bit worse than mine. I have 141,XXX on the odometer and will keep tis thread informed if the issue persists, or grows. for now, I'll just use 4L when going up a grade in reverse. Thanks,
Jon
 
Bumping this old thread. My serial number is 97DE07079 so outside of the 3 TSBs noted here. Has anyone else had this behavior and not been within the scope of the TSBs?
 
I'm going to bump this one as it seems most applicable to my case. It sounds like it fits what's discussed in the TSB, more or less.

It's also a reminder that you should go by the Transmission Serial Number. We have a Nov. 1996 production date for a 1997 model year vehicle.

Thanks goodness for smartphones and their capability to take pics in tight places. The # is clearly 96K E17563. Perhaps our truck ended up with an earlier transmission at some point?

From what I've read here and elsewhere, this may mean that it still needs the 3 o-rings. Or perhaps not if the TSB service was accomplished back in the day. Would any Toyota dealer be able to say if a service like this was accomplished?

I suspect not, as the truck does the same grind 'n stumble going into R from time to time as others have described. Does using Low range actually overcome this? Want to do Black Bear someday, but not with something like this going on. I've managed to live with it for years, but since I've been fixing things the last six months I've finally gotten 'round tuit. Would like to confirm where the truck is at with this to come up with a solution. None of this is very noticeable with our minimal terrain around here, but the mountains are no place to be getting doubts about getting into reverse.
 
If you haven't done so yet register on the Toyota owners website and plug in your vin as an owner and you can see all work that has ever been done at a dealer. Since this was a TSB it almost assuredly would have been done at a dealer.

Fwiw, and you probably don't want to hear this but my transmission was shot. Had nothing to do with the TSB. Drain some atf and see what color it is. If dark your reverse clutches might be burned up. I swapped transmissions with a low mileage 80 and the problem went away. Transfer case had no bearing on the issue, at least in my case.
 
Patrick,
Thanks for the Toyota records tip.

Oil looks good and doesn't smell like a fire went on inside so hoping things are basically OK. I've only had the slippy/grindy noise a few times, little enough that it's usually a surprise since it's been so long since the last time it happened. Towing our M101 CDN leads to more backing up that tends to make it happen.
 
Well, Toyota claims they only time they ever saw it was the one time I brought it in when we first bought it. I had a couple of significant issues with that they seemed oblivious about, so haven't been back since for service, (although they've since changed hands so I may try them again.)

So with nothing about any TSB work and the symptoms from time to time, I suspect our tranny still needs the 3 O-rings. As Rick and at least one other noted, if I can out up with the symptoms, might as well wait for the need for more significant service that requires it to come out for either R&R or tear-down/rebuild.
 
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*BUMP*
Good afternoon Mud:flipoff2:

Might have just found the same issue. I've never had an issue even doing the Rubicon 6 months ago.

I did do the ATF flush with 9 gallons of Valvoline red ATF, not sure if it's connected but it looks like I have a few options like draining filling the pan and having a look.

I swear when I'm standing on the passenger side front end it sounds like that's where it's coming from.

Situation causing the issue:
While measuring the shop door in preparation for a new roof rack, my wife was backing the 80 up into my shop over the curb to get in. She didn't gas it over the curb she just kept gently putting on the gas more and more and more and the truck wasn't moving until it finally crawled up the curb but it made that sound. I suppose this would have happened eventually but getting it to recreate itself only happens in reverse on a hill and hitting the gas super hard, ",load"

Normally driving shifting is clean and super crisp, I'm also 4:88 geared. I was thinking about rebuilding the Tcase as a preventive maintenance winter job but after reading here on mud and specifically this thread I don't think it's coming from there.

Fixes and research:
1. I'll pull my serial number and compared to what @landtank posted
2. I'll plan to drain and fill my transmission pan and report back
 
Good luck. Sucks the reman A343s are NLA. That's a pretty big regret of mine not getting one while they were still available. The low mileage one I swapped in has been flawless though.
 
Good luck. Sucks the reman A343s are NLA. That's a pretty big regret of mine not getting one while they were still available. The low mileage one I swapped in has been flawless though.
It is what it is, it'll probably run another hundred thousand miles ;)

I don't have any of the major symptoms listed like loss of power or anything like that it just makes it horrendous noise. However, the horrendous noise is probably a precursor of worse things to come I'll tear into it see what I can find out.

On the subject of NLA I'm going to snag a factory Short block I think this year before those become unavailable.
 

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