99 4Runner AT Transmission won't engage

Hi Guys:

I am new here and appreciate any help. I have a problem that has stumped my mechanic. My wife has a 99 4Runner with only 198K KM ( about 124K Miles), in pretty good shape overall. She purchased it brand new in 99. The problem started about 6 months ago when you drove at high speed(above 40mph), and then slow down to a stop, not abruptly stopping, but slowing down when you are just about stopped, you could hear a "clunk" as if there was a loose U-joint, but there was not. My mechanic could not find any problem. Now, in the past 2 months, if you drive at high speed (above 40mph), for 15-20 minutes and come to a stop(again not abruptly), there is no more noise....However, if you come to a complete stop, then you try to accelerate, the motor revs up, but the truck is no moving. If you turn off the engine, and turn it back on, most time it will be fine, but there are some times when you have to let it sit for a few minutes(while off) and it will be fine. The odd time, if you change gears (R-N-D), it might kick in. Here is the interesting part if you slow down to stop but you don't completely stop, and accelerate again, it is fine. The transmission doesn't feel like it is slipping either. The mechanic replace the tranny fluid and took the pan down, clean it, there was a bit of crud but nothing excessive, probably never been done before. Any help would be greatly appreciated. Thanks in advance to everyone.

--
Dan

 

As far as the clunking is concerned, it could be a number of things, assuming it's not a bad u-joint, it could be worn bushings in the control arms and/or loose sway bar / sway bar endlinks. If you have vibration at speeds I'd definitely take a look at that u-joint again though. It's reallllllly hard to definitively say it's not bad while still in the driveline. Also if you havent greased the driveline zerks (theres like 9 or so of them) definitely do that, it's been known to address that sort of clunk.

The other issue is more odd, but I'm going to assume the easy solution here, and you just need to replace the shifter bushings, theyre little plastic bits and theyre known to wear, especially in our older trucks. Super simple DIY job if you google it and less than $20 worth of parts. My guess is the shifter isn't totally engaged on occasion due to the worn bushings

 

Hi Roboturner:

Thanks for the reply.
There is no more clunking now, but when the mechanic checked it, he said all the Ujoints were tight. The mechanic is an ex-Toyota certified mechanic employee, he specialized in Toyota and has been for over 40 years. There is no vibration or anything feeling loose, I took it up to 100mph and it rides very smoothly. I am pretty picky when it comes to unusual noises, vibrations, or pulling, I usually notice all the little things. To me, it feels like the transmission is disengaging when you come to a complete stop. If you release the brake, when you are at a light, normally with an automatic, it will try to move forward, but it doesn't. That's when I know I have to shut it down. The thing that gets me is why it only does it when it stops if it were the bushing, wouldn't it do it any time? I will look into the bushings, I am at a loss as to what it could be. I normally drive a manual transmission. I just hope it is not the transmission, trying to find a new transmission will be pricey, I don't know how reliable are the rebuilt transmissions here in Canada. My wife doesn't want the new 4runner because they are much bigger than hers now. She wants one that the back window will roll down...only on the 4runners.

 

Although I’m not usually a parts cannon guy, just replace all the tranny/shifter bushings - cheap and probably needs to be done anyway, I’ve got $5 USD (~$6 CND) that’s your issue! - if not, there’s plenty of A340 trannys out there from wrecks in the junkyard, you’ll be fine- would be a lot harder to find a solid manual tranny

 

Thanks, I was looking at the truck tonight and there is no excessive play with the stick though?

 

Odd clunks are often the torque converter locking up when it shouldn't ( or partially unlocking at highway speed ). The other issue is way beyound my pay grade.

I am having a transmission rebuilt for a '99 i'm restoring at a local shop that has serviced my Highlander; I mentioned to the shop owner that Toyota converters seem to "flash" more as they age. He acknowledged that is true. We will replace this one.

Not being anywhere near a pro on Toyota transmissions, I will say there are a number of electrical connections I had to remove. Maybe a faulty internal solenoid, etc?

You might find a reputable and well versed transmission tech to diagnose it. These "slushboxes" aren't simple manual boxes.

I am having a large Continental shop here in Buffalo NY bench rebuild mine. They seem to be very familiar with these.

PS while removing the transmission ( for a new engine) on this 285,000 miles '99, I noticed yellow chalk marks on the pan - a junkyard trans to be sure. So as mentioned, the other route IF the trans is at issue, is to find the numerous replacements available at yards, at least here in the States.

( as a amatuer Chevelle restorer - crossing the border with car parts can be iffy as you may know! )

 

Hi 427L88, it doesn't look like it is a bushing, as mentioned in a previous post, now the mechanic is suspecting it might be a pressure valve issue. It is very odd behavior, it doesn't do it all the time, mostly after getting off the highway and coming to a complete stop.....Still scratching my head....lol
--
Dan

 

Cant imagine a bushing, that's stiff or imprecise gear selection mostly. Like a turbo, coming off a highway and coming to a stop gives a temperature spike. Yet, ?? IDK how that relates to a transmission, transmission fluid or torque converter operation other than the converter lock-up mechanism possibly. Anyway, no pro tech here, so wish you happy hunting.

PS I once disconnect a Ford rental truck speed speedometer years back trying to cheat, and the converter sort of freewheeled w/o that input in the system. You couldn't get it to 30 hardly redlining. Pressure switch, errant sensor?

as said best of luck Dan. we all hate anomalies like this ; can get spendy to solve.

 

I've got a similar problem. I suspect internal trans issue. I'd be interested in hearing opinions too.

 

what did you end up doing?