2007 Tundra 4.7L w/A750F - Shift issue

[tnt31]

Recently purchased a 2007 Toyota Tundra with a 4.7L engine and the A750F 5 speed trans w/152K miles. Purchased about 5 months ago. When it is cool and even worse when cold (the colder it is the more likely it seems to occur) sometimes when I first take out for the day it does not want to shift out of first. I usually have to back off the throttle a bit even though not accelerating quickly at all to get it to shift. Currently now that it is hot outside this rarely occurs. I was thinking of doing a fluid spill and fill then a pan drop, replace filter, and fill with new fluid to see if it will help however I will not likely know until it starts getting cooler if this corrects the problem. I do not think the fluid has ever been changed from talking with the previous owner. He seemed very meticulous with maintenance except for the trans. I also noticed Trans Go and Sonnax both make shift kits (links below) that both claim corrects common issues with the A750 (and some other models) transmissions.

Thoughts on if the fluid and filter plan has likelihood of success in correcting the issue I described above or if one of those kits likely a good investment. The transgo kit is a little cheaper however includes a drill bit so drilling something required which makes me a little nervous although I would have a shop install it. The Sonnax does not have the drill bit (and I do not think requires any drilling) however although a little more expnsive seems to have more parts included in the kit. I like the truck and plan to keep it long term.

Transgo

Sonnax

 

[Astro14]

Get the fluid level correct before anything else.

Cold shift issues are a classic low fluid symptom.

A pan drop and fluid change is easy. You’ll need about 14 quarts, a way to add fluid (really long funnel, but I use a pressure vessel like a garden sprayer) and you’ll need a way to measure trans temp. I use Techstream.

Drop the pan, change the filter. Refill with about 4 quarts. Pin the trans thermostat open, disconnect the cooler return line. Idle until a couple quarts come out, refill with that amount. Repeat until the fluid is red and clear. Reconnect the line. Unpin the thermostat.

Get the trans to temp and set the level. Done.

 

[supton]

Is the 5AT a “sealed“ transmission and sans dipstick? cannot find in 30 seconds of searching, sorry. Concur with getting fluid level correct. Changing fluid is a good idea but likely not the issue imo.

I think the filter is actually a strainer and as such likely not worth the effort to drop the pan. Not unless you really want to look at the magnets. There may be value in a good fluid exchange and then getting the level correct, and then evaluating the situation.

 

[GSCJR]

Sounds normal to me @tnt31 , it's in the programming. Toyota holds first gear longer (increase RPM), in order to warm the engine faster. This explains why it doesn't happen when ambient temperature is higher.

 

[clinebarger]

Sounds normal to me @tnt31 , it's in the programming. Toyota holds first gear longer (increase RPM), in order to warm the engine faster. This explains why it doesn't happen when ambient temperature is higher.

^^This! Though maintaining the unit is also a good idea.

 

[Bullet]

There has been a lot of reports of the problem and many of them have said it's normal. I think my 2006 Tacoma as the same transmission and I've never experienced that problem, but I don't think it has hit teen temps here in SE La except maybe a few times.



While not the same truck and along time ago, I had a 2year old 1994 Dodge truck do the same thing. On cold days sometimes 1-2 was late, but after the first shift it was fine. Fast forward to about the 6 year mark it one day never made it out of first. Dealership rebuild it under warrant and was told it was the one of the clutch pistons.

 

[tnt31]

Is the 5AT a “sealed“ transmission and sans dipstick? cannot find in 30 seconds of searching, sorry. Concur with getting fluid level correct. Changing fluid is a good idea but likely not the issue imo.

I think the filter is actually a strainer and as such likely not worth the effort to drop the pan. Not unless you really want to look at the magnets. There may be value in a good fluid exchange and then getting the level correct, and then evaluating the situation.

Yes, this is a 'sealed' transmission.

 

[Marcozi]

Sounds normal to me @tnt31 , it's in the programming. Toyota holds first gear longer (increase RPM), in order to warm the engine faster. This explains why it doesn't happen when ambient temperature is higher.

Actually, engines warm up faster when they are subject to lugging. I short shift my car from 1st to 3rd when I leave the garage for the first time.

https://www.collinsdictionary.com/us/dictionary/english/lugging

 

[CT Rob]

Is the 5AT a “sealed“ transmission and sans dipstick? cannot find in 30 seconds of searching, sorry. Concur with getting fluid level correct. Changing fluid is a good idea but likely not the issue imo.

I think the filter is actually a strainer and as such likely not worth the effort to drop the pan. Not unless you really want to look at the magnets. There may be value in a good fluid exchange and then getting the level correct, and then evaluating the situation.

Yes because we cant be trusted to check and refill the transmission . And the lack of a dip stick saved them a few bucks i guess.

 

[tnt31]

Sounds normal to me @tnt31 , it's in the programming. Toyota holds first gear longer (increase RPM), in order to warm the engine faster. This explains why it doesn't happen when ambient temperature is higher.

^^This! Though maintaining the unit is also a good idea.

Thanks for the replies

A few questions if you do not mind for a service on this transmission.

Fluid - Is VML MV good fluid for this application or do I need to get the Toyota WS? Other local options are Idemitsu TLS-LV or Castrol Trnasmax ATF/CVT MV, Ordering options AMSOIL OE Fuel efficient, Valvoline Extended Protection MV,or Aisin WS. If the VML is their any difference in what you get from Walmart vs the parts stores (or ordering from Valvoline) other than price?

Filter/Gasket - Do I need to get from Toyota or is the Wix 58136 a good option?

Thanks

 

[Astro14]

Anything that meets WS spec for viscosity, etc. is fine. Mine is running AMSOIL. Filter brand doesn’t matter much, it’s not much of a filter.

Yeah, it’s sealed, but that doesn’t mean unserviceable. See my previous post. Fluid changes will help its life.

When you said you have a shift problem, I thought it was actually a problem.

Your truck will shift at higher RPM when stone cold to aid in cat heating, for earlier light off and lower emissions. It’s not about engine warm up, it’s about catalytic converter warm up.

 

[tnt31]

Anything that meets WS spec for viscosity, etc. is fine. Mine is running AMSOIL. Filter brand doesn’t matter much, it’s not much of a filter.

Yeah, it’s sealed, but that doesn’t mean unserviceable. See my previous post. Fluid changes will help its life.

When you said you have a shift problem, I thought it was actually a problem.

Your truck will shift at higher RPM when stone cold to aid in cat heating, for earlier light off and lower emissions. It’s not about engine warm up, it’s about catalytic converter warm up.

Thanks for the reply. I guess descibing it as a 'shift problem' was due to I have never had a vehicle act quite like this however it is the first Toyota I have owned.

 

[Astro14]

Thanks for the reply. I guess descibing it as a 'shift problem' was due to I have never had a vehicle act quite like this however it is the first Toyota I have owned.

Yeah, the late shift out of first/second when the engine is stone cold is actually common. All of my automatics do it, Volvo, Mercedes, Toyota.

That said, now we know why, which solves the immediate concern.

But I would still flush the fluid on your A750. I’m about to do it a second time on my Tundra.

 

[GSCJR]

Thanks for the replies

A few questions if you do not mind for a service on this transmission.

Fluid - Is VML MV good fluid for this application or do I need to get the Toyota WS? Other local options are Idemitsu TLS-LV or Castrol Trnasmax ATF/CVT MV, Ordering options AMSOIL OE Fuel efficient, Valvoline Extended Protection MV,or Aisin WS. If the VML is their any difference in what you get from Walmart vs the parts stores (or ordering from Valvoline) other than price?

Filter/Gasket - Do I need to get from Toyota or is the Wix 58136 a good option?

Thanks

I use VML in Toyotas, head over to WM and get some. The WIX filter is a good option also; good luck!

 

[Toy4x4]

I've had Amsoil in the 4Runner trans for a few years now. No problems at all.

 

[Ursatdx]

I did mine (11 5.7) using the trans cooling lines.
Did not drop the pan as I was concerned with breaking a pan bolt(s) in the process.
Used the paper clip thru the OBD port method to check fluid level.
VML

 

[ARB1977]

My 15 Tacoma holds first gear for a bit on initial start. I have Maxlife and Amsoil SS blue cap in my 5 speed. Also added this a few years ago.

 

[tnt31]

Just a small update.

Not any specific reason that I can really quantify but I have decided to use the Valvoline EP MV ATF. Fluid should be here Friday. I already have the Wix Trans Filter. Hopefully my Indy can get me in next week to do the service. Also going to do an oil change with Napa Syn 5w-30 and Toyota filter.

 

[MalibuRam65]

Just a small update.

Not any specific reason that I can really quantify but I have decided to use the Valvoline EP MV ATF. Fluid should be here Friday. I already have the Wix Trans Filter. Hopefully my Indy can get me in next week to do the service. Also going to do an oil change with Napa Syn 5w-30 and Toyota filter.

That Valvoline is good stuff and should work well in your tundra