Changing a 91 G50 to a 94 radiator question

[OwnerCS]

Last fall I picked up a 94-96 style radiator at a bargain when it arrived by mistake on a 91-93 style order. So I've been sitting on a 94-96 model dual ATF cooling chamber style radiator in the box that I can replace the single ATF cooling chamber in the 91.

Today I visited the local pick-and-pull and picked up a nice looking fan and clutch from a 94 model. The plastic fan has no cracks. I noticed the 94-96 fan seems to have a more aggressive blade pitch than the 90-93 model fan. Would it make sense if upgrading the 90-93 type radiator to the 94-96 style to also change the fan blades, clutch, and fan shroud to the 94-96 model?

I actually have a new 90-93 model plastic fan still in the box. If I don't use the 94-96 model fan and clutch, I may list the units for sale as it appears to be a keeper.

I also have a new OEM ATF filter for the 94-96 dual style radiator that I intend to replace with the radiator upgrade job. The only hitch in this is the ATF lines from the engine compartment to the trans are the single port 90-93 style. I was looking into a line swap but that appears be quite an involved process with the cross-member in the way.

What would you do?

[elwesso]

The difference between the 90-93 and 94-96 on the fan is the 90-93 has a less wide, but larger OD fan, where the 94 has a smaller OD but wider blade fan.. Other than the trans cooler, i don't think much is different on the physical side of the radiator. In other words, I wouldn't worry about switching to the newer style fan and shroud.. Its possible also that the 94 fan pulls less air than the 90-93 since the early ones were sans grille, but who knows?

I am not 100% certain how the ATF circuit works on the 94's, never really cared to investigate it much. However the way I would do it on your setup is have a cross-over from one side to the other on the radiator, so basically its getting a "dual pass".. So have the fluid go in the bottom on one side, out the top, in the top, then back out the bottom, through the filter, and back to the transmission.. Thats how I would set it up.

Better yet, just ditch the radiator heat exchanger for a proper external cooler..

[OwnerCS]

The difference between the 90-93 and 94-96 on the fan is the 90-93 has a less wide, but larger OD fan, where the 94 has a smaller OD but wider blade fan.. Other than the trans cooler, i don't think much is different on the physical side of the radiator. In other words, I wouldn't worry about switching to the newer style fan and shroud.. Its possible also that the 94 fan pulls less air than the 90-93 since the early ones were sans grille, but who knows?

I am not 100% certain how the ATF circuit works on the 94's, never really cared to investigate it much. However the way I would do it on your setup is have a cross-over from one side to the other on the radiator, so basically its getting a "dual pass".. So have the fluid go in the bottom on one side, out the top, in the top, then back out the bottom, through the filter, and back to the transmission.. Thats how I would set it up.

Better yet, just ditch the radiator heat exchanger for a proper external cooler..

I'm on the same page with the heat exchanger routing. I do have one of the "standard club issue" Hayden/B & M external coolers that I planned to mount between the radiator and the A/C condenser coils for running fluid through it after leaving the radiator heat exchanger.

[elwesso]

Honestly I think thats making things more complicated than it needs to be. Just skip the radiator heat exchangers and go right into the external cooler.

[OwnerCS]

That will make the job easier. I was kind of worried about all of the hydraulic lines running around under there might start to take on a Citroën appearance.

[Infinitiguy19]

Their is less back pressure by using the OEM heat exchangers and the auxiliary transmission cooler inline.

[Lokim]

Honestly I think thats making things more complicated than it needs to be. Just skip the radiator heat exchangers and go right into the external cooler.

That's what I did, and I have had the same transmission fluid in for nearly 10K and it is still bright red and smells new. This is after multiple trips to eastern WA last summer driving up the pass in 100+ degree heat. I'm due for a fluid change, but definitely believe the way to go is delete the factory cooler and go with the B&M unit only.

[maxnix]

Remember the later ones had the external ATF filter also. Seems like the fan pulley was different also.

[qship96]

I will throw in my 2 cents worth of information ........the proper routing for the use of the dual coolers is as follows.

single line delivering atf from transmission goes into the oem atf filter cartridge by battery- it exits the filter via 2 separate ports on the bottom of filter with 1 hose going to each in-radiator heat exchanger......the output line from each exchanger{1 hose each} then gets connected to a Y pipe adaptor where it connects to a single line back to the transmission.


If you decide not to use the in radiator coolers for the atf {using an external cooler instead}, then you might want to use a single, or both in radiator coolers for cooling the power steering fluid by rerouting the PS return line through them


*********************** IN MY EXPERIENCE, using the dual in-radiator coolers as designed {for the 94-96 models} {to cool the ATF} is sufficient to optimize the life of the transmission, and the power steering does not need any additional cooling modifications......282,000 miles on original transmission and PS pump and rack lead me to that conclusion. If you track the car, or drive it like a teenage boy who just got his license......your results may differ,as the saying goes.

[OwnerCS]

My driving pattern is mild to say the least. Suburban driving during off peak periods with some I-40 driving. I don't take it out of the garage during extreme hot or cold periods..

[elwesso]

I tend to agree with you Qship, and thats great info about the actual transmission cooler routing.. Always wondered exactly how that worked... Never really bothered to figure it out..

I only suggested the external transmission cooler route to simplify everything.

[Lokim]

I will throw in my 2 cents worth of information ........the proper routing for the use of the dual coolers is as follows.

single line delivering atf from transmission goes into the oem atf filter cartridge by battery- it exits the filter via 2 separate ports on the bottom of filter with 1 hose going to each in-radiator heat exchanger......the output line from each exchanger{1 hose each} then gets connected to a Y pipe adaptor where it connects to a single line back to the transmission.


If you decide not to use the in radiator coolers for the atf {using an external cooler instead}, then you might want to use a single, or both in radiator coolers for cooling the power steering fluid by rerouting the PS return line through them


*********************** IN MY EXPERIENCE, using the dual in-radiator coolers as designed {for the 94-96 models} {to cool the ATF} is sufficient to optimize the life of the transmission, and the power steering does not need any additional cooling modifications......282,000 miles on original transmission and PS pump and rack lead me to that conclusion. If you track the car, or drive it like a teenage boy who just got his license......your results may differ,as the saying goes.

I never thought of running the steering fluid through the radiator... You're a genius!

I generally drive at approx. 70 mph on the freeway when I'm not stuck in Seattle's gridlock, but I got the car at 192K and it had horrible transmission fluid (purple w/ a pearlescent look and terrible smelling) when I got it. I decided to get rid of the factory transmission cooler and use just the B&M so I can try to keep this transmission alive to 300K. I figured in light of B&M's claims of the capacity of their cooler, it would be better than the stock cooler running through hot coolant. After a pan-drop and filter change right when I got it, a standard flush a week later, and a BG flush 3 months after that, it is shifting great and I am optimistic.

As for the steering system, the end seals on the rack were leaking and I basically had a continual flush going on for a few months until I got around to replacing the rack. The pump feels fine, no groaning or bubbles in the fluid, but I'd still like to keep the fluid cooler due to the amount of traffic I sit in. I'll probably use Lube Guard's "Kooler Flush" product to clean the lines and then plumb in the steering fluid line along with a magnafine filter.

Maybe I can use the other circuit to cool the engine oil...

[Infinitiguy19]

Using the OEM transmission cooler on the radiator as a power steering cooler would increase the capacity of the power steering system.

[Lokim]

Using the OEM transmission cooler on the radiator as a power steering cooler would increase the capacity of the power steering system.

Nothing gets by you, Paul!

[OwnerCS]

I will throw in my 2 cents worth of information ........the proper routing for the use of the dual coolers is as follows.

single line delivering atf from transmission goes into the oem atf filter cartridge by battery- it exits the filter via 2 separate ports on the bottom of filter with 1 hose going to each in-radiator heat exchanger......the output line from each exchanger{1 hose each} then gets connected to a Y pipe adaptor where it connects to a single line back to the transmission.


If you decide not to use the in radiator coolers for the atf {using an external cooler instead}, then you might want to use a single, or both in radiator coolers for cooling the power steering fluid by rerouting the PS return line through them


*********************** IN MY EXPERIENCE, using the dual in-radiator coolers as designed {for the 94-96 models} {to cool the ATF} is sufficient to optimize the life of the transmission, and the power steering does not need any additional cooling modifications......282,000 miles on original transmission and PS pump and rack lead me to that conclusion. If you track the car, or drive it like a teenage boy who just got his license......your results may differ,as the saying goes.

Here's how it turned out..

Basically I routed from the output side of the dual lined 94-96 model ATF filter into the 94-96 model radiator, I picked up a brass barbed connector hose T at the local hardware store for routing back to the single ATF return line. It took all day but it works. I think adding an external cooler is simpler, but I already had the 94-96 model ATF filter and radiator sitting on the shelf in the workshop.. Anyways, I can use the external cooler on the I30..

The only upgrade item that I have sitting on the shelf for installation is a 94-96 model drive shaft. I planned to do that upgrade if the 90-93 drive shaft starts making noise or I'm really looking for something to do some weekend -- which I don't see happening for at least another year..

[OwnerCS]

Now that the radiator has been changed to the 94 model, and I'm running the 94 style ATF filter, the shop said the only way they will go forward with an installation is to flush the system lines with a BG flush machine.

The shop requires the (three week old) ATF filter to be replaced because it has been contaminated with fluid that contains particles from when the torque converter disintegrated. Also, they will not use ATF cooler on the radiator if it is determined the cooler is accordion style because it cannot be adequately flushed.

I already have a new in the box B & M - Hayden style ATF cooler (that is the accordion style btw) just in case the radiator cooler area cannot be flushed.
I need to determine if I should switch the ATF filter from the single in dual out style to a single in and out -- thus going with a Magnafine filter.

Stay tuned to see how this turns out.

The shop says BG makes a fine synthetic ATF. Any suggestions for ATF on a newly rebuilt transmission?

[Infinitiguy19]

Mobil 1 Automatic Transmission Fluid (ATF) is said to be the best off the shelf stuff money can buy. But its not cheap at ~$9 a quart Especially if your using it for a flush.

BG makers some good cleaner products but I can't trust there fluids (I never used them).

[qship96]

Are you rebuilding your current transmission? I would use the cheapest genuine dexron ATF you can find to refill the transmission after initial rebuild/install......because I would run the rebuilt transmission for about 5000 miles, then replace all the ATF again as studies show the majority of wear particles in ATF occur during the breakin of new parts in any auto transmission.I would use a high quality Real, true 100% synthetic atf for this second fill- then simple 4 quart drain/fill every 15,000 miles for as long as you own the car using the same synthetic atf. Magnefine and aftermarket cooler is fine if carefully installed and plumbed.

[OwnerCS]

Are you rebuilding your current transmission? I would use the cheapest genuine dexron ATF you can find to refill the transmission after initial rebuild/install......because I would run the rebuilt transmission for about 5000 miles, then replace all the ATF again as studies show the majority of wear particles in ATF occur during the breakin of new parts in any auto transmission.I would use a high quality Real, true 100% synthetic atf for this second fill- then simple 4 quart drain/fill every 15,000 miles for as long as you own the car using the same synthetic atf. Magnefine and aftermarket cooler is fine if carefully installed and plumbed.

Good points. I'm going to the the L10 transmission from Wes then send it to L10 for a torque converter and freshening up.