Try this for smoothing out your tranny

[Astro14]

It's 60,000 miles young. I did change the fluid about 8,000 miles ago - been getting random harshness ove r the past 6 months. I thought maybe since it had never been changed since I first changed it that one more drain+fill+transtune couldn't hurt.

The 2-3 flare in a "new" transmission is concerning...it simply shouldn't be doing that...have you changed the fluid at all since the replacement? I am sure you've mentioned it in another thread, I just can't remember...I know the forum consensus seems to be 30K for changes and the owner's manual says (in a very small note) that if used for taxi/police it should be changed at 52K. Color of the fluid can tell you a lot about its condition...and without knowing that the fluid is in good condition, it's hard to pin down a mechanical problem...see SJonnie's post on fluid condition...

When the replacement was done 60K ago, what was the source? Without trying to be critical, there aren't any "new" transmissions...they are all rebuilt, including the ones from Volvo...so I am wondering if the B4 servo cover was replaced with the updated part...that can cause the 2-3 flare as the B4 band engages 3rd gear...

I've tried the transtune in my '90 Toyota - the high-mileage tranny (which has had the fluid changed regularly) engages OD a little better than it used to...certainly, it's done no harm...but though they're both Aisin-Warner transmissions, the A340H is a simple piece of gear compared to that AW55-50SN...

[JayPinNC]

I changed the fluid shortly after I bought the car at about 125,000 miles (about a year ago) . It had some flare then too, but the fluid definitely made a difference - and now I only get the odd random 2-3 flare that (to me) has not rhyme or reason. But 2-3 flare is still 2-3 flare.

The replacement transmission was put in around 70,000 miles at Don Beyer Volvo in Alexandria, VA.

I had posed a similar question about the B4 servo cover - meaning, sure it's a 'new' transmission, but 'new' is a relative term. It could be new to the car and still have the old cover.

I'm going to check that out if I have a chance tomorrow.

Part of me thinks I need to go test drive an XC of similar vintage to see how it shifts, or a newer model to see how it's supposed to shift. Even my Corolla gets some minor flare in certain circumstances.

I did drain + fill the XC today and will see if it made any difference. I left the Transtune in for about 200 miles.

[TexasXC]

Read this

I read that - in fact I had already read through the flush procedure.

Never saw mention of real world experience wit flushing a high mileage tranny that has never been flushed...ipd says to watch out for flushing a high mileage car as the clutch packs could not work with the new fluid (not sure how much I believe).

I have been scared off flushing from the dealer and ipd - but my gut still makes me think "new fluid > old, used up fluid."

Anyone take a >100k tranny and flush for the first time? Good, bad, or indifferent?

[Astro14]

Took a 90K tranny on an '02 and did the flush. Improved things for a while. When the minor shifting issues returned, I flushed it again...improved for a while...and then went through the flush one more time...

Ultimately though, mine was one of the problem years. I replaced the B4 servo cover and the valve body at about 126K and it's been great ever since.

In your case, the more cautious approach would be a drain and refill...about 3.5 QTs...half the fluid. Easy to do. Make sure the fluid is JWS-3309 (I like the Mobil 3309 but have use Toyota T-IV with good results...).

The reason that high-mileage trannies fail when flushed (and they do, it's not a myth...) is that they're already shot. The bands and clutches are completely worn out...but you can't tell because the fluid is so filled with wear particles that it provides extra friction that hides the worn-out parts. Put clean fluid in, and suddenly it doesn't work...and folks blame the flush...when really, the tranny was already toast...

I think I would avoid the seafoam unless you add an external filter as well. With the seafoam, I wouldn't want to dissolve some gunk that then circulates unless there was a filter to catch the bigger particles. Oil already has detergent in it...new fluid will slowly clean the trans...best to go slowly in your case, I think...

[dejanaleksov]

That is so true.my box is almost dead after a flush.Thanks for the knowledge Astro. Cheers

[NTXC]

If someone is doing this should they remove the amount of fluid that the sea foam would displace? Or is there no problem in adding this as-is? I’m just looking for clarification because I don’t think that has been spelled out clearly for those of us who don’t have the level of knowledge of Astro or Howard here.

[A.Lucas]

I drew out 300ml last month and put in same amount of the TransTune and I do think it shifts better, especially 2nd to 3rd. I'll put an additional 300ml in sometime soon. 2006 with 225K miles on original transmission and its working great (especially after the Polestar upgrade).

[Rabid Koala]

I bought some Seafoam before my first fluid exchange several years back but didn't have the stones to use it. The trans shifted much better but was not perfect, the second fluid exchange I installed a cooler and that took care of the problem. I'm due for exchange number three now.