transmission technician

I have an '02 Tacoma, 2WD, 2.4L and 5-sp manual trans,~85k miles, completely stock.

A few days ago I started having trouble engaging 4th on my 3-4 upshift. The problem became more pronounced over the weekend such that now the trans won't stay in 4th. It will hold 4th under acceleration but letting up on the throttle causes it to come out of gear. Not having the problem in any other gear. What am I looking at? Is this a shift fork problem? Something worse?

I bought the truck in '06 with only 40k miles on it, I believe I'm only the second owner. Before last week I've had exactly ZERO problems with the truck. I usually do all the work on my vehicles myself but haven't dealt with manual transmission problems.

 

Gear Cruncher, I have a 2005 2wd Tacoma with 130,000 miles on it. I took it to my Toyota dealer for a transmission flush and was told that it is not required on my transmission since it"s a "sealed unit". They did say that the fluid looked good. What is your advice on whether I should take it back and get it flushed?

 

I haven't seen GC in here lately. My diagnosis would be a bad synchronizer for 4th gear.

I would take it to an independent shop that has the correct flushing machine and ask them for an estimate on the flush. Dealerships are trained to only follow what the manufacturer recommends, not what is seen in the real world. That is the only down side there.

 

Agree with bama on the synchro .

I forgot I made this post hehehe . Most guys just pm me now

 

Oh NOW you show up!

 

Thanks for your input and suggestion.

 

GC,

I've got an '08 DCLB Sport, auto XMSN w/V6.

For some time now, when getting on a highway or accelerating up to 70 mph, the XMSN is not shifting and I will hang around 3K RPM. Odd thing is, I can move the shift from 'D' to '4' and back to 'D' and it will drop in gear and RPMs will settle back to 2.1K. The quick maneuver from D-4-D has a seamless shift. However, the XMSN will not shift on its own at highway speeds without my manual input.

I did take it to the dealership and they proceeded to tell me that it was the lift that I had on my truck and bigger tires (33s)...I thought they were full of $hit and left. No codes being thrown...I was thinking a bad synchronizer?

This has been going on for about 8 months and I guess I've gotten use to just manually moving D-4-D. Your thoughts?

S/F,

 

Synchros are only in manual type transmissions, so it wouldn't be a synchronizer. The only sure-fire way to know for sure is to have a scan tool that shows transmission data and see what the manual selector input, and transmission fluid pressure switch data say. If they are out of sync then it could cause some transmission shifting errors. I will say that running larger tires will change the "engine load" condition that the ECU uses to calculate shift points. I am not going to instantly say the dealership is right, because I don't see any cases of a transmission error like this on 33 inch or smaller tires. That being said, different engine loads can cause the ECU to "hang" in a gear for a much longer time. The more throttle you give it at that point the longer it will actually STAY in that gear. Try driving on a flat, even road surface. When you get up to the speed where you have this problem the most, try to ease off the accelerator to see if it will upshift when there is a low engine load. If that doesn't work, get up to about 5 MPH faster and let off the gas completely to see if it upshifts. If it does upshift either time, then you may be looking at a load issue, and not a software or component failure.

 

Interesting what you mention at the tail end. Other than me manually moving gear from D-4-D again, I can also let off the gas at 70 mph and give it about a "three Mississippi" count and it will upshift. Unfortunately, backing off the gas at highway speeds and the delay usually isn't conducive to Texas highways. That's why I've been using the 'ole D-4-D trick. Since the XMSN will upshift with me backing off the gas, you think it may be a 'load issue'?

What would you recommend as options for mitigating this issue?

Sure do appreciate your time and input...great gouge!

S/F

 

I agree with Bama . Your issue does sound load related . Are you sure Toyota scanned the ECM for codes ? The reason I ask is the transmission is completelly computer controlled and they wouldnt be able to advise you properly unless they diagnosed the problem following Toyotas, guidelines .
. Did Toyota road test with the scanner connected paying close attention to the final upshift ?
There are many sensors and solenoids that come into play to obtain 5th gear .
Whats the mileage and have you kept up with the transmission servicing .

 

GC,
Thanks for the input. I do know that they kept the truck for a few days after they too said they could replicate the problem with the upshift. They brought in their top guy and he recommended swapping out the tires with a stock vehicle on the lot to test a theory. At that point, Toyota told me that they did not experience any problems with the upshift..."it's your tires." Gotta admit, that I've not taken it to another service shop.
As for servicing, all is current and I stand at a little over 84k miles. This one upshift to 5th is the only problem I'm experiencing, otherwise, it runs fantastic.
Again, sure do appreciate ya'll taking time out of your day to provide some TW expertise to the problem.
S/F

 

There are a few posts on shifting issues for 5th gear but all deal with early clunky shifting when the transmission is cold .The clunky early shifting can be fixed with new accumulator seals . The only other thing I can think of is a faulty SLT solenoid . With this said , the electrical portion of the solenoid still functions fine thus " no ECM codes indicating a fault code " but a mechanical issue with the solenoid itself getting stuck or partially stuck .
On your next trans service , I would replace the SLT solenoid
You can read more about the issue here
http://www.tacomaworld.com/forum/te...hift-kit-shift-recalibration-kit-2nd-gen.html
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Hi Gearcruncher, I experienced some strange slippage in my auto transmission today and would appreciate any wisdom you can throw my way to figure out why. Tacoma is a daily driven '99 TRD V6 + automatic with 137,000 miles. I have had it for 12 years and have only flushed the tranny once, about 7 years ago. No leaks anywhere and dipstick shows it's 90% full of red/brown ATF. Symptoms are slippage in taking off from a stop in drive gear only and hard shifting/clunk when coming to a stop. It does not seem to do this at all if I use the lower gears to take off or stop, reverse works normal as well. Suddenly started doing this halfway home from work today. Temp was around 85 degrees out and I had already driven a couple of miles with no issues. Really slipped bad as I came into my driveway. I let it cool down and tried to diagnose it with my limited knowledge. Just in case it was computer related, I disconnected my battery for a while and topped off the tranny with fresh ATF. Connected the battery and put the transfer case in neutral. Started the truck and went through all the gears without the drivetrain load to make sure I could not hear any clunks or noises while the transmission was spinning and to try and circulate the ATF a bit. Seemed fine so I went for a test drive and there was no change. Seems to slip for about 2-3 seconds when accelerating from a stop in drive then spins out when it finally catches. This suddenly came on with no warning today so I am hoping the tranny is not worn out. Could this be a stuck valve, clogged filter or maybe a bad fluid issue? Should I limp it over to Jiffy lube for a tranny flush and see what happens? Thank you for any advice!

 

You topped up the trans ? how long were you running low on fluid ?

From your explanation , I would be making an appointment at your local transmission shop to have the transmission proffesionaly diagnosed .
Your transmission is computer controlled and I beleive when you select drive range , the transmission actually uses 2nd gear in automatic mode for the initial application into forward to avoid lurching and then downshifts into first gear . With this said , there may be an issue with the shift solenoids because we know the transmission functions fine when you use the lower manual gear selections .
Your issue is a common concern but there are a lot of variables to the cause .
It could be a stuck valve or possible wear on the valve http://www.sonnax.com/parts/2745

it could be a partially plugged sump filter .
These are just 3 possibilities and there are many more that can cause your concern .
With this said , its in your best interest to have a shop diagnose the issue rather than guessing or assuming . Most shops offer a free road test and can usually give you a good indication of whats going on just by driving the truck .

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Thank you for the advice. I will be taking it in soon. Have a great day.

 

If you really like your 33's, then another solution to your problem, is to re-gear the differential(s) to match the 33" tires. That should trick the ECM into thinking its stock, and solve the load issue.

 

Thanks Rick...

Two questions for you:
1.) Would a re-gear cause the truck to run at a higher RPM?
2.) What would be the recommendation on the gear ratio?

Gotta luv TW...

 

When you swapped to 33's, it caused your motor to run at a lower rpm to maintain the same speed, acceleration became worse, top-end increased, and speedo should be reading off (lower than your actual speed).

Re-gearing should put you back to 'normal', including restoring your original rpm's.

The gears to install needs a calculation that depends on the diameter of your original tires, and your current gear ratio. A reputable gear shop will determine the right gears. Cost is around $500 per axle, so if you have a 4wd, it would cost about a grand.

 

Hey Gear Cruncher I hope you can help me with this problem. I think it is a transmission problem, but don't know for sure.

I have a rattle on cold start up. It doesn't seem to matter what the outside temperature is. The rattle is not present until I start to move (forward or reverse) and it goes away after I drive a few miles. It also seems load related since it does not happen when coasting in gear. If it happened when I was not moving I would describe the sound like a heat shield might make. It does not seem to be speed related either. Any suggestions?

06 Double Cab V-6 4X4 automatic long bed 118,000 miles.

P.S. I tow this vehicle behind a motor home in Park with a drive shaft disconnect on the rear differential. Trany and transfer case flushed and still no difference.

 

I would still consider the heat shields possible . When the truck is under load , there is a slight twist to the drivetrain components and when you take your foot of the gas pedal to coast , the drivetrain relaxes .
Try to duplicate the sound in your driveway by performing a stall test .
Scroll to page 20 and perform a stalltest http://fjcruiser-club.com/docs/RM/A7...0Transaxle.pdf