Transmission Flush not recommended for 850's

[Hoov]

can see issues with power flushing, such as forcing fluid through valves the wrong way, pushing 'dirty' fluid back into bearings, or blowing out filters, seals, etc. But I imagine a lot of the yocals doing flushes are not aware of the consequences of ramming fluids backwards through the valvebodies and bearings, filters, etc. I have taken apart transmissions with 150k plus on them and they looked factory new in terms of the fluid deposits. They had wear, but weren't varnished at all.

Yeah! Good common sense thought! I'm new too but nice to see your post. Like you, I want to participate where I can but I'm probably going to learn more than I can teach. If you have to climb into the cylinder to remove the rod bearing I can probably help but when it comes to cars I just know about the ones I've owned. Amazes me the volume of information here & the willingness of some of the folks here to share their experiences. LOL ... I'm at the point now where I'm thinking "Don't start working till the camera batteries are charged!" ... Fortunately for me, at this point, most of the work I need to do is already very well documented. Very fortunate because, thanks to the folks here, I aleady know some of the pit falls & what to expect.
Sounds like you will have more to contribute & I look forward to more of your thoughts.

Hoov ...
Yeah! That really is my name! LOL, Short for "Hoover". First name is "Bob" but haven't heard that for a long time!
Glad you are here!

[FastLane]

Thanks, "Hoov"!

I agree, this is a great site and its nice to see people contributing. I have also seen a lot of this on VW and Audi sites as well since I also do all my own work on those vehicles as well. Volvos don't seem to get tinkered with as much, but there are people doing it and they love to share and show off their baby, nothing wrong with that! This is a great resource, make sure you use it.

Welcome to the forums and I'm sure we'll talk more.

Mark

[FastLane]

I did the drain & fill using (as suggested by a mechanic from Volvo) CASTROL ATF+4.
Now it shifts rough but not much.
Next, I am going to do another drain & fill, but before that, I'll add the Sea Foam Trans - Tune ...

Does the Seafoam really work? I'm a fan of Lucas oil additives, and I have seen guys on the VW/Audi sites actually 'sipping' Seafoam into their intakes via a vacuum hose to clean valve bodies, etc.

What does the ATF version of Seafoam do for you?

[Craigd2599]

I am a Lucas Oil devotee. As for top engine cleaning I prefer GM Top Engine Cleaner over Seafoam.

[polskamafia mjl]

If you guys do a search for seafoam on this site you will find a really long thread where a lot of people have talked about their experiences w/ seafoam. A lot of people swear by it but there is a significant number of people who hate it though.

[Craigd2599]

So fellas tell me something...if you aren't using a power flush machine but only sucking in fresh fluid at the same pressure the trans operates at, what is the risk? I understand using a machine that forces it in a higher pressures and against the normal direction of flow, but basically using the flush described here you aren't doing anything to the trans that the trans isn't doing every time you drive. Am I missing something?

[phat78ta]

So fellas tell me something...if you aren't using a power flush machine but only sucking in fresh fluid at the same pressure the trans operates at, what is the risk? I understand using a machine that forces it in a higher pressures and against the normal direction of flow, but basically using the flush described here you aren't doing anything to the trans that the trans isn't doing every time you drive. Am I missing something?

Speaking from my personal experiance, it will take all the crud that may possibly be holding the trans together(ie the grit from the clutch plates) and rinse it all out. then the fresh shiny new innards of the trans are scrubbed clean of what was making it hold, and it begins to slip in a most horrid way. I found this out th hard way. NEVER FLUSH A HIGH MILEAGE TRANS!!! I got lucky and found a 78k unit at a local salvage yard, and with the istall I'm only gonna have @ 700 wrapped up in the replacement. I know I could have done it myself, but I lack time and am scared crapless of front wheel drive transmissions. i'd hate to break something and have to hear it from the wifey.

[jblackburn]

Drain and fills a couple times in a couple weeks-months period if it hasn't been done before, then "graduate" to a flush after that if you are comfortable with it. That would be my advice for the "safe" route anyway.

My transmission was immensely happy to have a flush done, it had 155K miles on it at the time I think. I switched it to Mobil-1 in the process, and I have never felt it shift so smooth. I recently did it again 12,000 miles later.

Since I didn't know (that) history of the car, I went with a two drain and fills first, then chanced it and flushed the whole thing.

[Timberwolf530]

OK, a distinction needs to be made here. Alot of people are getting transmission "flushing" mixed up with the DYI article for replacing your tranny fluid on this site. That method is not a flush. It's just a way to get all the old fluid out while simultaneously replacing it with new fluid. I have been using that method on my trannies for years, and it's a little messy at first until you get the system down, but it's perfectly safe. Flushing actually uses a machine to force a cleaning solution through the plumbing of the transmission in the reverse direction. This could dislodge gunk that may "relodge" itself somewhere you don't want it to. The DYI replacement works great as long as you take it slow, and pump out the amount the pan holds, then fill it back up and repeat until it's pumping new fluid. All major brands of synthetic fluid today are backward compatible with dino fluids & completely safe for seals and gaskets. It's never too late to start using synthetics. The only disadvantage of synth fluids is the cost. I would not recommend flushing on any vehicle no matter how many mile are on it, but you won't hurt anything doing the DYI replacement method.

[marginal]

I swear by synthetic oils and lubricants ...
Expensive ???
How much more expensive would it be on a Volvo transmission for instance?
Maybe $15-20 ???
Can you call that expensive on something you do once in 5 years?
Also, on a unit worth a couple of thousand $$$ to fix and / or replace ???
This is not expensive to me.