Most Everything You Think You Know About Trannies Is Wrong Topic is solved

[packetfire]

I today resurrected a 2001 v70 transmission at 289K miles by merely installing a rebuilt valve body with the assistance of the buyer of the car, who won his bet on the rebuilt valve body, and thereby got a much better deal on a car than he otherwise might have.

In researching this issue, we spoke with a fellow who we both know socially. He rebuilds transmissions for a living, and his views sharply contradicted much of what I have read here and on other Volvo-aficionado forums.

Here are some quotes from him, for your education:

Change the fluid, and never, let me repeat, never use an inline filter.
Trannys are lubricated by cooler flow. Stop that and all your bearings are gone.
Bad enough you have a burnt clutch, now all your hard parts are trashed also??? Not a plan.
By the time that filter catches anything your transmission is already done.

Tranny fluid has 3 purposes, it's a Hydraulic fluid, and a coolant. For those purposes water works fine. The last and most important is lubrication. When tranny fluid gets old it loses its viscosity and lubrication properties. From that point the valves and solenoids wear out (bearings also but they are last to go). Valve wear is what causes 90% of tranny problems.

Fluid wears out on a time/temp slope higher temp, faster wear. Longest you should ever go is 100k... and in town I would say 30k, you run a lot hotter driving in the city than us country folk. Most tranny cooling comes from the airflow over the case.

Second coolers can be a good idea, but for most cars not worth the problems. It adds some potential leak points, and more resistance to the lines so it's a balance between more cooling and reduced flow.

The method where someone adds a magic cleaner chemical is a joke. Totally asinine in reality. There are some contaminates in the unit. Mostly clutch material and a tiny amount of metal. What happens though is that thru centrifugal force they are spun outward in the Torque converter, and in the clutch drums. They are compacted into place in areas that they are completely harmless.

No amount of cleaner will dislodge them.
A lot of it here has to be scraped out after a cycle in the parts washer.

The "flush concept" is only slightly better in that you are getting rid of more of the old fluid.
Note I did not say all, as to get about the 90% mark requires about a 6 gallon flush.

The best and easiest method is a partial change dump what you can, replace, repeat. 2-3 times.
You can do a dump but the best way is just take it to a shop that has a flush machine, run you around $150, takes a lot of fluid to do it right.

The people who worry about a flush machine doing damage don't know that a tranny runs at 70 to 200 psi (varies with load) flush machines operate at 35 psi. They are not going to cause anything to fail, the problem is that too many people resort to changing the fluid only when the tranny is already dying, so they blame the flush machine.

You can tell if your fluid is bad. Put it between your fingers and rub. If it is like water and only slippery for a second or two, its junk, fresh fluid is like cooking oil, stays in place and stays slippery.

[jonesg]

That has the ring of truth to it . Good info.

[vtl]

Does your buddy also suggest to avoid using oil filter in engine?

Filters have a bypass valve. When the filtering surface gets clogged, excessive pressure opens bypass valve. Worst case dirty filter is not doing any filtering.

[packetfire]

Does your buddy also suggest to avoid using oil filter in engine?

I'm not here to argue, I was just reporting the views and wisdom of someone who rebuilds transmissions.

The clear difference between an engine oil filter and a tranny oil filter is that the engine oil filter is directly attached to the block, and presents minimal risk of an oil leak. The tranny oil filter, on the other hand, is kludged onto one of the cooler lines, and (he says) can pose both the risk of leaks where it is spliced into the line, and the risk of blocking fluid flow through the cooler.

I have no idea which, if any, filters have bypasses, or how they might work. I was just echoing the advice of someone who had my best interests at heart, and would rather see me simply change the fluid annually than install a filter.

[FlyingVolvo]

My own anecdotal experience: I've had an inline filter for about 100K with no issues (current mileage is 238,000). I also installed an aux trans cooler in front of the intercooler, no problems there. Transmission is definitely aged, but it still runs very well 95% of the time. I'm pretty sure it would not have survived my many heavy hauls in the Southern heat and Western mountains without the filter and cooler, but obviously that isn't proven scientifically!

The first time I replaced the Magnefine filter at about 50K the media didn't have much in it (I had done a series of drain & fills previously), but the magnet had caught a bunch of fine metallic particles. The second time changing it about 40K later yielded far less junk.

I'm happy with it. Thanks for posting the advice! I think for the most part those are some very good guidelines. I can only offer what I've experienced, but that's what we're all here for!

Cheers.

[polskamafia mjl]

Most of that information is sound advice but I must agree his stance on inline filters is boggling. I will add however that several veteran members on this forum have cautioned against trusting tranny shops so that's something to consider as well.

Either way, the evidence we have on this forum suggests that regular drain and fills are the single most effective way of ensuring long transmission life.

I was just echoing the advice of someone who had my best interests at heart, and would rather see me simply change the fluid annually than install a filter.

Perhaps he's looking forward to you paying him to change that fluid.

[packetfire]

Perhaps he's looking forward to you paying him to change that fluid.

Nope, he is several thousand miles away from me, he rebuilds trannies for shops, he does not do anything else but rebuild them, and has no retail side to his business.

He honestly wanted to correct my misconceptions.

[RigsPGT]

I'll stick with an extra cooler under the egg crate and remember to flush the tranny at 30k miles. If Volvo or any other car manufacturer have designed auxiliary transmission coolers, I think I'm OK.

[precopster]

About filters; in the Aisin 4 and 5 speed transmissions the filter is embedded so deeply in the transmission that relacement is a rebuild job. Changing fluid helps to prevent blockage of this filter.

If the filter blocks it can be perforated and bypassed as I did with my 2001 T5 recently with the addition of an.inline filter.

However I have a friend that owns both a Subaru and a Hyundai and he told me both of his cars have external screw-on screw-off filters. He was surprised that Volvo's filters aren't servicable.

[abscate]

An engine oil filter is designed in by the engine-eers who made the motor - they worry about where it is, how it is fed

A hack like me slapping in a filter with hoses and toy clamps is not an engineer, and is not privy to the feed and flow needs of the transmission, and, aside from leaks, its no wonder these things cause more trouble than they are worth.