posted by
someone claiming to be charles
on
Sat Mar 1 10:45 CST 2008 [ RELATED]
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Hi everybody and hope you all doing well.
I have two 1994 940's turbo and non turbo,and wondering if anybody has successfuly installed a seperate transmission oil cooler in their car.I am not confortable with oil sitting with antifreeze in a radiator waiting to be mixed someday.
Can you please provide details about doing this job, and is an oil cooler out of a 740 turbo big enough by itself to do the job?.
Thankyou all in advance and have a great day.
Charles.
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I thought that someone was bound to be making this, so I looked.
http://store.summitracing.com/partdetail.asp?autofilter=1&part=PRM%2D1060&N=700+115&autoview=sku
This reduces the flow of oil through the cooler until it is warmed up.
Alternately, some coolers seem to have this built in.
http://www.bmracing.com/index.php?id=products&sid=4&cat=20&subcat=28&pid=73
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While that may be a good idea for racing applications, it is EXTREMELY unreliable in real world conditions. You absolutely DO NOT want to have this in your daily driver. Chrysler tried this in their transmission cooling setups to help with converter drain back issues. When a unit comes through the shop that has a valve of some sort in the transmission cooling system, it is immediately removed or replaced or no tranny warranty is given. These things are prone to excessive failure.
You are WAYYYY better off just letting the car idle in gear with your foot on the brake for a few minutes to warm it up. If you want to warm it up fast, put it in gear and hold the brake and rev the motor until it seems to bog down and hold it there for about 30 seconds. This is a stall test and can overheat and destroy your transmission if you do it for too long. It will dramatically heat the tranny fluid quickly though.
just my personal experience.
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I installed a Hayden cooler in the front of my radiator on the 86 240 (B230F) almost three years ago prior to towing another 244 for 10 hours back to Charlotte from Western Kentucky. The car has been on a 12 day road trip to the West Coast and back at altutudes of 9000 feet and within the last two weeks made a trip to Western Florida and Western Kentucky without missing a shift. While it is improbable that you will have a failure in the radiator with the stock system, the tranny will run cooler with an aftermarket unit.
Regards,
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Will Dallas, www.willdallas.us, www.willdallas.org, www.willdallas.com, www.dallasprecision.com 86 245 DL 222K miles, 93 940 260K miles, 88 765 GLE 152K miles
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I wouldn't say improbable. I have a 940t and for awhile, I was doing the tranny cooler in radiator system, and the radiator broke, the coolant and trans fluid started to mix. Not long thereafter, the tranny broke (my car is not stock though). Anyway, on the next tranny, I swapped in a 35,000lb cooler from a ford truck. Used a 4' wide bar cut to fit across the frame rails of my car, bolted it to the frame rails, then did a bit of trimming to the front grill supports. Works a treat and the tranny cooler sits nicely up front. I bent the stock coolant lines down and just extended them a bit with some autozone tranny line. I will admit its a bit ghetto, but with double hose clamps, it has yet to leak. It handles the load fine with my brick and with the power my car throws at it, everything is all right.
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Volvo still sells them but they are aux coolers. You really need a good surface area to do this right. I would guess it would have to be 1/3 or 1/2 the radiator size with cool air intrusion.
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This is a good idea although... I would recommend simply adding the transmission cooler inline with the one already in the radiator. I am a transmission tech and to tell you the truth, the scenario you describe is one I just don't see very often. Overheated transmission fluid though, I see as a cause of major repairs consistently.
Hook the new add on cooler up in line before the radiator. This way, in the winter, the fluid can be rewarmed a little if needed by the radiator cooler. This, (fluid being too cold), is as far as I know, only a problem in the coldest most northern most climates.
In the summer time, it may be possible to cool the transmission fluid cooler than the radiator thereby acting as a small heat transfer to help maintain a cooler radiator temp. This should all still provide a reasonably cooled transmission fluid back to the sump. It will be dramatically cooled from the time it left the transmission on it's journey, and you won't be adding any or as much heat to the radiator and could possibly remove some. You shouldn't overlook the potential for cooling that exists along the transmission lines on their way back to the sump either.
The transmission and coolant both have temp sensors and I would suspect that keeping the temps somewhat relative would keep the computer happy as well. Though I am not sure what the computer strategy is based on the input of these two sensors together, or if there is any at all.
Either way, it should be beneficial. I wouldn't completely bypass the original cooler unless it was stopped up from previous transmission failure. If you don't keep the trans cool enough you will definitely have problems. Heat is the #1 enemy of automatic transmissions of any brand.
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volvodave240, appreciate the knowledge and advice and this is not a negative response. I do not believe these robust, probably over designed by today's standards, AW70 series trannys have a temp sensor or a temp controller. No electronics just some electrics.
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Yeah, I don't know really. I was just thinking out loud really, most other cars you have to take things like this into consideration though. I never heard of a radiator problem like this that was inherent in Volvo's design, but I don't see a lot of Volvo's where I live. I just changed markets though and start a job in Charlotte next week so I am sure to be working on a broader range of vehicles now.
Also, like I said before, I never had to work on one of mine so I don't know about the electronics on any Volvo units off the top of my head, or any others really. Except maybe Chevy trucks, see so many of those, and Chrysler FWD. Other than those two units and maybe one or two more, my take home knowledge is considerable less than my at work knowledge if you know what I mean. With so many units on the road today, it is hard to remember much about any but the most common, without having to say, let me grab the book.
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I've dealt with tranny coolers in my Astro vans and I've heard the same thing about using a separate cooler that the fluid might be too cold in the winter.
What exactly is the problem with it being too cold? Does that harm the transmission?
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hello
over the years there have been very many folks with trashed transmissions on the brickboard when the engine coolant mixes with the trans fluid.
maybe its a volvo thing? or most cars here are kinda old.
volvos factory tranny coolers on the older 7 series turbos are pretty small and as i remember its goes into the radiator before it flowing through the cooler.
that being said i know almost nothing about transmissions.
i put aftermarket coolers up front and bypass the radiator which has just a small strip running through the radiator, then plug the holes where the cooler lines were connected.
good luck
mike
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"i put aftermarket coolers up front"
I do like the idea of a no radiator oil cooler. What is the size of the cooler? As touted in the faq, synethitic ATF runs cooler and if true it would probably be a good idea.
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The interior/radiator tranny cooler can be so small because fluid-to-fluid heat transfer is so efficient. Fluid to air is extrememly inefficient.
jp
--
Jeff Pierce (Post back with your results... it's what makes this forum work.)
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Be careful with the POSTS below. not sure if those Coolers are in Addition to the Radiator or totally Remote units.
You can buy Coolers that will handle the Trani without running through the radiator. Look in 4 wheel Drive type magazines and websites. Auto parts stores sell them. I have a unit on my Jeep, I've been driving it 13 years that way. no issue even with trailering a 20' boat. I recommend isolating it from the radiator for the exact reason you mentioned.
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.no.net/ebrox/Tony's%20cars.htm
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Hello there, I have a 93-940 and the radiator failed a year ago, mixing coolant and tranny oil, what a mess, so I replaced it with a brand new radiator ($120) and flushed the tranny and cooling system several times.
Well, I decided to install an external radiator for the transnmision, I went to the junk yard and saw several GM SUVs that had a nice plate tranny radiator in the front, they are like 11"x8", I bought it for $15, flushed it and that's the one I have used for a year now.
Every time I go to the junk yard I see them, they are very common in GM small suvs and they are all in good shape.
Also, Chrysler mini vans like Voyagers, Caravans and Town & Country they all use an external tranny radiator in front of the A/C condenser and you'll find millions of them in the yards.
The only problem with this: tranny oil works well when it's NOT very cold, if it's too cold outside the oil will be over-cooled by the incoming air flow, so the idea of passing the oil inside the radiator prevents this and keeps the tranny oil at the same temperature of coolant, some cars have a temperature valve that bypasses the cooler if the fluid is cold, but I haven't found that valve yet.
I really don't worry too much about that since I live in South Florida.
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I have been thinking about this, too. The PO of my 740GLE had her transmission replaced twice because of radiator leakage. I just replaced the radiator myself because the old one was ten years old and full of petrified transmission oil.
I saw this one, but I'm sure there are others: http://www.autopartswarehouse.com/details/QQVolvoQQ740QQ4-SeasonsQQTransmission_Oil_CoolerQQ19851992QQFS53001.html
Hope I've helped. I think I might just replace my radiator regularly to keep my transmission safe.
Ari
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The OEM system is pretty reliable, but if it gives you peace of mind, have at it.
The design of the 740 tranny coolers is horribly inefficient at transferring heat. So if you're going to go to the trouble of installing a separate cooler, you can find one of much better design at any auto parts retailer (local or online). They're generally marketed for truck that will be towing a load. They will have comprehensive installation instructions.
jp
--
Jeff Pierce (Post back with your results... it's what makes this forum work.)
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