At about 40,000 miles my 4.7 4x4 starts to slip on the first 3-4 when it's cold. I have Toyota look at it, they can't recreate the issue. OK, I learn to take my foot off the gas on the first shift of the morning. It still annoy's me so I have a fluid change and a new trans filter put on. This fixes the slipping on the 3-4 shift awhile , but a new problem start's. Now if I make a harder than average stop, the transmission get's lost during the downshift's. It's basically in neatral and you have to come to a complete stop for literally one second to allow the trans to find a gear. If you do a partial stop, or accelerate before this "one full second" the tranny does a nuetral drop and you do a ten foot burnout.I have Toyota check it out, THEY SAY IT"S NORMAL! Finally at 1500miles over my warrenty, third starts to slip. My local tranny shop says it's a $3500-$4000 job! The tranny shop and I both think it's a loss in line pressure. Anyone else have similar situations?

If it truly is line pressure, it is a blockage causing it. Try an Auto-Rx treatment. Link to purchase in my sig below.

Trucks back at Toyota today. Their "going to take care of me."
I guess the auto rx is worth a shot, but how will it fix worn frictions and glazed pressure plates?

..I guess the auto rx is worth a shot, but how will it fix worn frictions and glazed pressure plates?

It won't. If it has been operated in this condition for too long and the internal component damage is that severe, then a flush will prove it as it will remove the friction material ground off the clutch plates that is suspended in solution and the transmission won't shift anymore regardless of fluid pressure.

That's why any issue with a transmission needs to be addressed immediately, as waiting just increases the chances of irreparable mechanical damage and failure.

After two tranny shops and two Toyota dealers I have an answer!
It was two qts low on trans fluid. Where the trans fluid is going I don't know, because it doesn't leak. For now it shifts fine. Accourding to the shop manager these trannys are very difficult to get the correct amount of fluid in and need to be purged. However the slippage on the 3-4 shift started before I ever had the fluid changed.

After two tranny shops and two Toyota dealers I have an answer!
It was two qts low on trans fluid. Where the trans fluid is going I don't know, because it doesn't leak. For now it shifts fine. Accourding to the shop manager these trannys are very difficult to get the correct amount of fluid in and need to be purged. However the slippage on the 3-4 shift started before I ever had the fluid changed.

Check the condition of the coolant. The ATF lines run through the bottom of the radiator. A leak in here won't hit the ground.

However, I'll bet the last time the tranny was serviced, the tech shorted you 2 quarts. The manual with my vehicle is in error as well. It says a pan drains only 2.1 quarts when I know damn well it is almost exactly 4 quarts. This could be your answer.

Good to know. Thanks.

Well, I took my truck back last Fri. It would still slip , mostly in overdrive, at light throttle or 1500 rpm. It was'nt much or bad, but it wasn't going to get any better. Well four day's have gone by and I had not heard anything, so I gave Toyota a call. The Service Desk tells me that they are putting a new trans in. So the question is, does anyone know of a place that does valve body modifications for Tundras in the Chicago, Milwaukee area? IPT is a 10-12 hour drive for me and I'm not really comfortable doing the VB by myself.

Well, I took my truck back last Fri. It would still slip , mostly in overdrive, at light throttle or 1500 rpm. It was'nt much or bad, but it wasn't going to get any better. Well four day's have gone by and I had not heard anything, so I gave Toyota a call. The Service Desk tells me that they are putting a new trans in. So the question is, does anyone know of a place that does valve body modifications for Tundras in the Chicago, Milwaukee area? IPT is a 10-12 hour drive for me and I'm not really comfortable doing the VB by myself.

IPT's VB modifications are proprietary, so I'd find out exactly what you want done before shopping around for a shop that does "valve body mods".

I'm just looking for a firmer shift to prolong the frictions.
In shift kit lingo, I guess I'd want a stage one, or towing.

I'm just looking for a firmer shift to prolong the frictions.
In shift kit lingo, I guess I'd want a stage one, or towing.

Sorry if this comes across the wrong way but do you want take your truck to a shop that is going to tell you that they can modify your valve body but has really never done one or do you want to send it to the place that has done hundreds of them?

I think the idea is to extend the life of your transmission, not have your trans be an "experiment" for your local trans shop.

I can speak on this because there are exactly two shops in the country that do the mod and they are both in NJ.

I don't know if you've seen our YouTube videos, but the vb r&r is pretty straightforward. I'm sure that you can find a mechanic to do it if you aren't comfortable with it.

Also, TS members get a 10% discount on the modification.

-John
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