Installing a factory transmission cooler + Stat + Magnefine

[CNGBiFuel]

Installing a factory transmission cooler + Stat + Magnefine filter

Coolers, filter and stats have never been covered. With these cars getting on a bit, the penny seems to have dropped. Thus it's been done ten-fold - an ATF flush is a minimum.

More detail here:
https://www.volvoforums.org.uk/showthread.php?t=259661

It's been my hobby-horse for too long, and with the impetus pushed further, I've always gone way further because experience of the miles I do rather forced my hand. At 420K my set-up is a proven test-bed.

I've had a exchanges with RobertDIY over this, and we're in agreement - for real miles these cars are under-cooled. Here we stress, most of you will get by on flushes and if it's borderline a Magenfine too.
Robert does miles and prefers to do manual-conversions these days, but then a manual is a bit of novelty Yankside. So why not? And whilst - if I say so myself, the traffic on my stuff can't be sniffed at, our Robert does rather pull in more. I suspect his words have had a great deal to do with the current passion for flushes. Good on ya' Robert...


The Yanks reading this will, unlike my fellow Brits, often be found doing galactic miles. What we have here is for you. These boxes will do 400K 'if' looked after and kept cool, but you'll need lots of flushes or a set-up like below.

I likes a good Yank

And yes, for most of you, and the blokes flouncing around with remaps / big disc kits, 'noizzee zhorsts' and all the other 'no miles paraphernalia', what you see here is overkill....

[CNGBiFuel]

What you're looking at here...

Is the factory cooler as fitted some of the go-faster variants, and late C70 + a Magnefine inline filter + Derale Transmission Cooler stat.
Stat and filter nailed-down under the battery tray.

You see it now because this set-up is mid-swap from my last 'shed' and onto the next. Overkil for most, this is a 'must' if you drive the thing. The only things that will differ from one car to the next is the sizing for the Magnefine. I know there is difference, frankly I can't remember the details - More info on that later.

This will be an on-going thread. This mod is proven, I've done this myself three times. Unless you've done similar and can add info to this conversion, can we ask you to 'leave be' until we're done. Most of this has been done-to-death, thus.... Save the "I've got a car and I shan't tell you what it is, what ATF does it require?" threads for another day.

More soon...

[CNGBiFuel]

In short, heat is the enemy of an auto box.

That's hardly a revelation, they like good fluid. If it is pink it is ATF. Rose red is fine. If it is brown it is not ATF. It's burnt. Do not pass go do not collect £200. Yet, some seem to struggle with this concept, however.... ATF when cool stays pink. ATF does not go brown on its own. £500 says if your vehicle has no cooler, and has more than 30-40K on it, it's brown. By 90K a drop on the end of the dipstick is not pink, it's black.

Thus good enough for Volvo and their 'lifetime fluid' yet not much more.
Lifetime of the warranty.


1) To prevent your ATF going brown requires frequent flushes or a cooler.
2) To prevent the crud that comes off the friction rings blah clogging the valve-body, and causing flares, you'll need a filter.
3) A stat is probably over-kill for 98% of you, but if you can...

Points 1-3 don't apply if you either:

a) Flush lots
b) Have a low miler and intend keeping it that way.
c) Aren't worried when your box starts flaring.
d) You intend to keep to the miles Volvo expect within the warranty period.


Of course there's always going to be some lucky sod with 250K on his odometer running original fluid - but from what the rest of us have seen that'll be the exception. The rest of us should flush by 90K.

And pound-to-a-penny hte bloke that says "It runs fine on original at 250K" has a car with a box that feels more like a 1983 Renault auto. He's simply 'forgotten' how it is supposed to be.

More later.

[CNGBiFuel]

And listen up....

Here's the Brucey-bonus. It's a trick I've pulled off twice. Found with cars at 140K and 170Kish respectively, both should have been flushed long since. Both were showing mild flaring 'after' a flush.

Fitting a cooler and filter in both cases saved them. I suspect fresh fluid dislodged the crud in the valve-bodies, the fliter prevented return. The cooler kept the temperature-dependent flaring at bay. Thus the lesson is, catch it in time and this stuff works.

[CNGBiFuel]

More pix... I've put these up before, but now harm done, again.

The factory cooler hangs on the same bolts that hold the main radiator

[CNGBiFuel]

Factory blurb.... the differnence in the rads is the hose sizing. From memory you'll want a 1/2" Magnefine for four-speed boxes, 3/8" for five. I'm working on mine today - I'll verify later.

[CNGBiFuel]

For the bulk of you, the one thing you'd be wise to take from this is the filter. As I said, aside from heat-damage to your ATF, as the miles pile on, crud clogs the valve body. Leave it too long and clearing the crud from your valves and valve body doesn't help. The flaring damages the friction-rings, which produces more crud, and the downward spiral doesn't stop.

Those with 2002/2003 cars had real problems. Dealers would do a software box remap. This, like the software remap of P80 ETMs got them out of a warranty fix. Make your own assessment.

I can't speak for the four-speed box, but the Aisin Warner 5 speed variant does have a filter - it's not up to much. Good eough for crud up to warranty miles, I'm about to cut open my old filter. I'll post pix of what I find. Last time there was a heap of crud in there. The stock filter on 5 speed boxes can't be great.

Only I've just looked, a branded Magnefine is no longer a cheap item. It's the courier/delivery cost that kills this. [ I speak English for chrissakes I'm on a one-man crusade and refuse to have anything 'shipped']
Any in-line transmission filter will do, provided it has a magnet, and minded to the cost of a Magnefine you might look to something unbranded.

[CNGBiFuel]

Can't tell you I've used one, or if it's the right hose-sizing, or if it has a magnet, but something like this comes not cheap, but cheaper.

[CNGBiFuel]

In the event you run to the Derale Thermostat too - it has hidden costs. Fitted with Yank NPT threading the hose-tail / barb elbows are pricey. If they were BSP you'd run down you local plumbers' merchant. Far cheaper, the rest of the world uses BSP. With NPT, your fittings bill will be another £20-25. I don't think there's a BSP stat to be found.
My time again, I might be tempted to force BSP into the NPT threads. Yes, they' X-thread but with a dob of JB-weld they won't leak, and you're not going to be taking it apart again anyway.

[RollingThunder]

Interesting topic CNG, thanks for raising it.

An ATF flush is on my to-do list as my 850 has around 84k miles up now. I usually replace the radiator at 100k or so as preventative maintenance, so will include an aux transmission cooler and filter at that point.

One word of friendly advice though - you might want to ease off the aggressive tone a bit? I'm sure a lot of people won't actually read very far because of that, and so may miss out on some genuinely useful information

Keep up the good work, and please lets see lots of pics the next time you install one of these yourself - I'm interested to see where you're plumbing it in.