Hard shifting from 1st to 2nd gear while driving (1 Viewer)

[128keaton]

Hey folks, me again.

My '03 LX470 has been having an intermittent problem when driving where shifting from 1st to 2nd (taking off from a stop typically) made the car do a jerking/shuddering motion. Almost like a clutch skipping but only for a split second. Some days its very noticeable and hard, other days its as smooth as silk. ATF is very clean and does not smell burnt (03, non-sealed transmission). I figured it was my rear driveshaft binding (the splines were toast), but even after replacing, it still shifts hard from 1st to 2nd.

I tried to record a video, but you just have to be in the car and feel it. Frustrating! All the other gears are very smooth.

It does not feel like it would be the front driveshaft or front U-joints, but I'm not beyond eliminating them (they've never been replaced). Hub flanges are good and tight, no walking snap ring.

Looking back at the service history, the PO seems to have had repeated problems with the transmission or torque converter (replaced torque converter in '08, and again in 2010), which is not encouraging.

I've attached the relevant service history from LexusOwners.com if anyone is curious.

Thoughts? Should I just flush and add some sort of additive? Solenoids have already bee

4/25/08 (86k):

10/7/09 (110k):

6/30/10 (124k):

06/17/11 (140k):

6/30/14 (188k):

 

[128keaton]

One more from 2010

 

[gatormark91]

deleted

 

[jerryb]

hard to think the dealer would let someone run around for multiple years low on fluid, BUT, I'm sure there are stranger things out there. The 5 speed does exactly what your talking about if it's low. Surprisingly, its doens't take much to be low. IT seems to me that somewhere less than 10% low it will delay engagement in first and hammer into second with a tire chirp with a delay (part time 4wd). Worse after a hard stop.

 

[128keaton]

hard to think the dealer would let someone run around for multiple years low on fluid, BUT, I'm sure there are stranger things out there. The 5 speed does exactly what your talking about if it's low. Surprisingly, its doens't take much to be low. IT seems to me that somewhere less than 10% low it will delay engagement in first and hammer into second with a tire chirp with a delay (part time 4wd). Worse after a hard stop.

Interesting.

This is a new issue for me, so I don't think the dealer is to blame. Might just have a small pan leak after 233k. I'll add some when I leave work. Would be fantastic if it was this easy. Thanks Jerry.

Will report back if that fixes or not.

 

[jerryb]

I changed three radiators in it in less that a few weeks, Then it started being very consistent with the hammering. Took a few days to realize what I did. I added one qt after that and it stopped altogether.
Maybe you'll get lucky, maybe you've had a slow leak.

 

[128keaton]

I changed three radiators in it in less that a few weeks, Then it started being very consistent with the hammering. Took a few days to realize what I did. I added one qt after that and it stopped altogether.
Maybe you'll get lucky, maybe you've had a slow leak.

I'm figuring (hoping) that my driveshaft vibration was enough to cause some leaking under loads.

 

[128keaton]

I believe I was a bit low, so I added some and I will see how it drives more tomorrow.

 

[128keaton]

Well, I'd been working on finding the source of whining in my LX470, but after replacing both the serpentine belt tensioner, the other serpentine belt pulley, and doing a PS flush (all without fixing the whining), I believe my transmission is the source of the noise. More hard shifting, even with the fluid at the appropriate height. This morning was really rough.

Has anyone had an A750F crap the bed on them?

 

[128keaton]

Well I was driving to a local transmission shop and DTC P2757 popped up along with the VSC/TRAC and engine lights. Fun. This is on the car that has had the solenoid(s) replaced and torque converter twice. I can’t even find a thread with 2757 mentioned on the 100 series forum.

 

[128keaton]

Just got a call back from the transmission shop. The torque converter is FAILING. Third TC! What the hell?

For a replacement of the TC and rebuild, I'm looking at $3909.95.

not sure if its worth fixing or just selling off and driving a beater.

 

[97 AZ LC]

Just got a call back from the transmission shop. The torque converter is FAILING. Third TC! What the hell?

For a replacement of the TC and rebuild, I'm looking at $3909.95.

not sure if its worth fixing or just selling off and driving a beater.

Maybe you could swap in one of those rock solid four speeds.

 

[128keaton]

Maybe you could swap in one of those rock solid four speeds.

Oh yeah, I’ll get one of those MY2000 A343s. Rock solid.

The A750F isn’t a bad transmission. Searching for failures on mud results in very little data.

 

[Txagg007]

Can you get a good used one out of a wrecked rig and save some coin? 4k seems unacceptable.

 

[128keaton]

Can you get a good used one out of a wrecked rig and save some coin? 4k seems unacceptable.

That is currently what I am trying to find out. The A750F is a really common transmission among Toyota's:

• 2003-2009 Toyota 4Runner (4x4)
• 2005-2015 Toyota Tacoma (V6 4x4)
• 2005-2009 Toyota Tundra (4x4)
• 2004-2009 Toyota Sequoia (4x4)
• 2007- Toyota FJ Cruiser (4x4)
• 2003-2007 Toyota Land Cruiser 100-series (4x4)
• 2003-2009 Lexus GX 470 (4x4)
• 2003-2007 Lexus LX 470 (4x4)

Just not sure if anything varies between these vehicles and the A750F installed.

 

[97 AZ LC]

Oh yeah, I’ll get one of those MY2000 A343s. Rock solid.

The A750F isn’t a bad transmission. Searching for failures on mud results in very little data.

I was just kidding - such a swap would never be practical. I don't think the A750F is a bad transmission but the Toyota 4 speed hydraulic transmissions were extremely robust and long lived, internet legends on MY2000 aside. It seems like every manufacturer struggled with the transition from hydraulic 4 speed to electronic 5 speed. The early electronic 5 speeds in Europe were just ridiculously troubled. That was back in the late 90s but they obviously had no idea what they were doing.

 

[128keaton]

I was just kidding - such a swap would never be practical. I don't think the A750F is a bad transmission but the Toyota 4 speed hydraulic transmissions were extremely robust and long lived, internet legends on MY2000 aside. It seems like every manufacturer struggled with the transition from hydraulic 4 speed to electronic 5 speed. The early electronic 5 speeds in Europe were just ridiculously troubled. That was back in the late 90s but they obviously had no idea what they were doing.

Haha I understand, didn’t mean to come across snappy.