Harsh shift 1st to 2nd after ATF change?

[Starbuck]

To be clear, I did not flush the ATF. I drained via the drain bolt (didn't drop the pan).

The fluid level may have been low prior to the drain (I don't know, as I didn't properly know how to check the level). So, new fluid added = the amount released by the drain hole + any previously missing fluid. The prior fluid was dark, but not black. No idea when it was previously changed.

Prior to the change, some of the shift points seemed like they could be a little high, but, there was no slipping. It could also be normal and just me not used to it.

After the change, the shift from 1st to 2nd is notably more harsh, a bit of a stout jolt. And, this shift seems to occur at a lower RPM range than previously. In fact, the new RPM range seems more like what I would have expected. However, I am concerned about the harshness of the shift.

Any thoughts?

Should I drive it and see whether it 'works itself out'?

Should I drain and refill to change more fluid?

How about trying synthetic? (I used a Dexron which superseded Dexron II).

Other ideas?

Thanks.

[JDM VANMAN]

I had kinda the same issue on my 89 auto 112k miles when I got it, there was warped seal and a leak. The seals were inexpensive but the process was timely and expensive. I had the transmission dropped and the torque converter pulled and drained. There's no drain plug for the torque converter so it has to be turned upside down and swished around to try and get all the old fluid out. The T/C was put back in and I think 2 seals and the filter was replaced, and then it was ran/drain/filled a total of three times. The fluid had never been changed and looked thick and dark like oil, had that been neglected any longer I would have lost the transmission. After the service it did have some hard shifting from 1st to 2nd and even from park to drive but it seems to be running fine now for me. It's been about 15,000 miles since the service and when I had my oil changed the service writer recommended another flush. But at $180 just to drain and fill.... That's a bit much. I think I'm gonna try it myself of course after looking up a YouTube video on how to do it!!

[timsrv]

I've had the harsh shift issue on 2 or 3 vans. I think it's a common issue with these. It's much more noticeable on cargo vans as they lack the insulation that would deaden some of the jolt. Someone was telling me the valve body has some plastic check balls & over time these shrink and can cause this issue. Other than "driving comfort" issues, this is no big deal (won't hurt anything). I had one van I drove for about 80k miles with harsh shifting (particularly from 1st to 2nd). It shifted at the correct RPMs, it was just "bang" all at once. This was a cargo van and I did notice it was much smoother when loaded heavy. If yours is a cargo I would consider it normal.

I'm not sure if synthetic fluid would make a difference, but I like the Amsoil synthetic ATF. I've been running it for years & I feel confident with it. One thing I like is it can be mixed with other non-synthetic ATF. That's important because it's near impossible to get all the old fluid out of the torque converter (well, short of drilling a hole in it).........which btw, I have done before :wnk:. Tim

[gushaman]

from what i have heard, a soft shift comes at the expense of clutch pack life. I harder shift, so long as its not too hard, will be uncomfortable, but is actually less slippage at the clutch packs. someone correct me if i am wrong, i would have gotten this off a ford truck site, where a former ford transmission engineer is a regular poster.

[Starbuck]

Thanks for the responses. :)

Would it concern any of you (or anyone else here) that the noticeably harsh shift from 1st to 2nd manifested right after the fluid change?

It's weird, shifts 1st to 2nd at a lower RPM now. But, it is quite a harsh shift (whereas before it wasn't).

Any thoughts on a 'cure'?

[timsrv]

If something changes immediately after a service, it usually has something to do with the service performed. Maybe it had a different type of fluid and/or some additives before? It sounds like you got the fluid level correct. Not sure what else could have changed. When you say you used the fluid that supersedes Dexron II, I assume you're talking about Dexron III............right?

[Starbuck]

Here's a detailed breakdown of what I've done:

-Initially, prior to any ATF fluid change, I thought some of the shift points might be high (although it wasn't slipping). When previous owners had changed the fluid was completely unknown. It's also possible the shift points were normal for the 3Y.

-I did a drain from the drain bolt. I added some Dexron VI, and some Lucas Transmission Fix (just to see what effect it would have). The Dexron VI was all the store had, and, it claims to supersede Dexrons II and III. The Lucas is extremely thick, like honey. It took a while to go down the funnel.

-There was no immediate change to how it shifted. A few days later, I figured out the proper way to measure the ATF level. I determined I was about a quart low. I added a quart of Dexron VI. After this, the harsh, jerky 1st to 2nd shift manifested. Interestingly, this 1st to 2nd shift also began occurring at lower RPMs (which addressed one of my initial concerns prior to starting all this lol).

-I then thought maybe the Lucas was too thick. So, I did two drain and fills with Walmart Supertech Multi-Vehicle ATF (claims to cover both Dex and Merc). The procedure I followed was to drain, fill, run the engine for a few minutes, and then repeat. I figured this would replace a majority of the fluid in there. I used the Supertech as it was inexpensive, and the intent was to get rid of and dilute the Lucas.

-There has been no change. 1st to 2nd is still a harsh, jerky shift. It still occurs in the lower RPM range. All the other shifts are smooth and occurring as before I started changing fluid.

-My new plan is to try Valvoline Maxlife ATF (synthetic, and I believe they have one multi-vehicle one). I purchased a load of it at WalMart - 16 bucks for a gallon. I am thinking to do what I did before - drain, fill, run the engine a bit, and then repeat a second time. Hopefully, I will then have majority MaxLife, and we shall see.

Thoughts?

[trestlehed]

Did you check the condition of your auto trans kick-down cable?
A couple years ago my van began shifting strangely; delayed shifts/different shift points.
Turned out that the kick-down cable was frayed and ready to break.
Just something to look at and keep in mind.

http://www.toyotavantech.com/forum/showthread.php?711-automatic-transmission-delayed-jerky-shifts-throttle-cable-adjustment

[timsrv]

The only ATF products I've run in these transmissions have been Dexron II (while it was still available) and Dexron III. About 7 or 8 years ago I switched to Amsoil synthetic ATF as it was recommended by my transmission guy. Dexron VI is a synthetic too, but I was advised not to run that in these older transmissions (not sure why). I see it's listed as backwards compatible, but not sure about it's ability to mix with the older non-synthetic fluids. The other thing I'm not sure about is additives like Lucas (I've never used them). I figure the ATF manufacturers already make complete products that include all needed additives. Putting anything else in there could potentially "muck up" the balance. Even if it doesn't hurt anything, I can't imagine it improving things (Just my opinion). To be frank, I don't know enough about the products you're using to make recommendations. I just stick to what I know and feel comfortable with. If I inherited your problem and knew about the Lucas/Dexron VI, I would try to get it all out and go back to a standard Dexron III or the Amsoil synthetic ATF. I would also pull the pan and replace the strainer........but that's just me.

Like Trestlehed said, kick-down cable issues can mess up shift points, but shouldn't affect severity of shifts. If the kick-down cable sticks in the WOT (Wide Open Throttle) position then shifts won't occur until RPMs are high. If the cable breaks or becomes unattached shifts will occur early. Most notable when you need power and mash the throttle to the floor (early shifts = poor acceleration). Tim