AT won’t go into reverse when cold (1 Viewer)

[Craig Haworth]

Transmission just started not going into reverse often when cold, once warmed up, shifts and drives perfectly. Thought it might be low on fluid, but no dipstick to check, so not sure if that’s the issue. Has 275,000 miles on the clock, and thinking fluid and filter change is in the order, but some say not to change it fearing the old fluid is what’s keeping it from slipping.

Thoughts? At 275k, is it about time for a new transmission?…… or?

Have the issue with the left bank air valve stuck as well, but investing in the Hewit fix for that ($600), but hoping a new OEM rebuilt AT can wait till next spring or??

 

[linuxgod]

Not going into reverse I think means you’re looking at a transmission rebuild. I’m not an expert though. You can try to swap the fluid, I really don’t think it’ll hurt at this point. If you do a swap you need to follow the procedure to do all 12-13 quarts, not just drain and fill the pan

 

[Sandroad]

If you have no record of fluid change, for sure do that using @linuxgod suggestion for complete change. Maybe the new WS fluid will help the cold R shift.

 

[bronc076]

Sounds like a stickey shift solenoid. I can't imagine how bad that fluid is if it has never been changed. If it's not slipping yet you can probably save it and get some more miles out of it. Do like Linuxgod says. I'm about to do mine and it only has 100K, PO never had it done.

 

[TheComedian]

While you're on the subject. What do you think when you should change the oil in the manual transmission?

 

[bronc076]

My Tacoma owner's manual says every 30K to change the fluid in the manual transmission. I can tell by the way it shifts when it is time to change too. I know nothing about the manual in a 200 as we don't get those in the USA.

 

[bloc]

If you cold start then let it run for a minute or two before trying, will reverse work?

I vaguely remember something about the AB60F losing pump “prime” when not running, with miles on it and having trouble with reverse as a result. In that case giving it some time to pump fluid through and get the air out makes it shift fine.

This can present like “it works when warmed up”

Maybe worth a shot.

 

[gaijin]

If you cold start then let it run for a minute or two before trying, will reverse work?

I vaguely remember something about the AB60F losing pump “prime” when not running, with miles on it and having trouble with reverse as a result. In that case giving it some time to pump fluid through and get the air out makes it shift fine.

This can present like “it works when warmed up”

Maybe worth a shot.

I like this idea. I'm no transmission expert, but I vaguely remember from my early driving days in northern New England winters (-25 DegF), that it's a good idea to warm the transmission up a little before driving off - BUT the shifter should be in Neutral, not Park. The rationale offered to me was that more fluid pumps around in Neutral than in Park.

Is this true? I have no idea. But 60 years later I'm still warming up in Neutral...

YMMV

HTH

 

[Craig Haworth]

If you cold start then let it run for a minute or two before trying, will reverse work?

I vaguely remember something about the AB60F losing pump “prime” when not running, with miles on it and having trouble with reverse as a result. In that case giving it some time to pump fluid through and get the air out makes it shift fine.

This can present like “it works when warmed up”

Maybe worth a shot.

 

[bronc076]

I know of no difference in fluid routing in N vs P in any automatic transmission. I researched and I saw a couple valve body videos but none that IDs the servos quickly and I doubt most of the folks in the 200 room are interested in valve body videos. Nor in my quick search did I find any theory of operation regarding N -vs- P fluid routing but if it works for you, I say do it, it can't hurt, unless your truck rolls away.

Here is a fun video walking you through the components in the rotating portion of the AB60E/F transmission.



I do encourage people to regularly change your transmission fluid. I bought a 94K mile 200 and I'm doing a full change at 100K, and every 50K from then on out. I have an old fork lift at my farm in AR that leaks transmission fluid, so I have a good use for all the old fluid.

 

[Craig Haworth]

Yes, it shifts perfectly once warm, as long as it isn’t in limp mode, which should be resolved with Hewit module. Thinking we are looking at a transmission in the near future, but at 275,000 miles, I feel it’s acceptable! Will most likely buy a genuine Toyota rebuild.

Car drives beautifully once it’s warm and system rebooted which eliminates the limp mode.

If a new trans, the Hewit kit, and a few small water hoses gets us going for a few more years, I feel it’s worth it. If it needed much more, we would replace it with a newer LC 200.