Mobil 1 & Trans Temp

[Rex]

Was searching for something else and came across this on the carsurvey web page

"I have a '94 Q45 and I have towed a small boat. I have Tokico struts and have added a rear sway bar and the biggest problem is that it pulls so well that you have a tendency to forget what's out back. Now about the transmission. I installed a trans temp gage and found readings that were alarmingly high when towing in summer. Pretty high when not towing as well. I then did a fluid change to Mobil 1 synthetic and dropped temps more than 10 degrees! Best thing an owner can do for transmission longevity. I also added a large trans cooler which I located in the spot for the Q45A suspension fluid cooler. (Between of the drivers side front wheel and the fog light. The splash guard in the wheel well is already ventilated.) This cooler dropped my temps significantly. I have only exceeded 200 degrees on a couple of occasions in traffic and brutal heat. The transmission has been totally reliable as has the rest of the car. A further note about towing. Most boats are set up poorly on their trailers. This car cannot handle much tongue weight. Spend time and adjust the boat and trailer until everything works. It's time well spent."

Okay, after you get past the IDIOT :bash pulling a trailer with a Q, what do you think about the 10 degree drop in transmission temp with Mobil 1 synth? Was it the Mobil 1 or the change?

[PalmerWMD]

The transmission (with cooler) and engine can handle the boat fine.But any pull weight at all, is poison for our rear subframe assemblies.

I think the temp drop is possible with the newer and better fluid but didnt expect it to be so large.Keep in mind this is anecdotal.

Still a good interesting read about someone actually monitoring transmission temps and what the results were.

Fred...

[Q451990]

It would be great to see this guy on NICO!

Heath

[maxnix]

I think the temp drop is possible with the newer and better fluid but didnt expect it to be so large.Keep in mind this is anecdotal.

But it may not be anecdotal if he actually measured it before and after. Might not have had sufficient controls to affirm 10° F difference, but still an interesting observation.

[Q45tech]

10F sounds about right as Mobil 1 engine oil will do the same for oil pan temperature........and a premium diff fluid will lower that unit even more.

Probably has to do with the more uniform diameter [daltons] of the base oil molecules resulting in less friction in pumping the oils.

Synthetic base oil is more stable and has much less evaporation of the lighter components.[because there are none/fewer]........so the viscosity stays the same longer.Used oils/fluids get thicker and thicker placing more stress on pumps --------more heat.

Try 10 ounces of Lubeguard Red additive [to Mobil 1 ATF] it will probably lower the peak temp another 10F...........careful in using the Lubeguard Black [no more than 5-6 ounces] as the friction modifiers may make a worn lockup clutch unstable.....chatter/too rough.

Even conventional ATF will survive [overheating > 176F] if changed evey year...........but the heat breaks down the glue holding the friction material [and special paper gaskets] together.

So all in all what ever modifications keep the temp below 176-190F is the best............the coolant should not go above 195F and the oil in the pan above 210F [because the oil under the piston skirt/rings is 100F hotter.

Measure your diff conventional oil temp in Summer when towing and take a Valium.........why racers and even police cars have auxillary coolers for that also.

Ever notice that the PS fluid washes out the color faster than the ATF..........not enough cooling, small quanity, and massive fluid shear from the pump...........racks are cheap compared to transmissions or differentials.

[maxnix]

So all in all what ever modifications keep the temp below 176-190F is the best............the coolant should not go above 195F and the oil in the pan above 210F [because the oil under the piston skirt/rings is 100F hotter.

Measure your diff conventional oil temp in Summer when towing and take a Valium.........why racers and even police cars have auxillary coolers for that also.

Ever notice that the PS fluid washes out the color faster than the ATF..........not enough cooling, small quanity, and massive fluid shear from the pump...........racks are cheap compared to transmissions or differentials.

In reverse order, I note that a PS cooler was optional on the Z32, has anyone attempted to install one on a Q45? Both of my PS fluids (have yet to do the Y33) were only very slightly darker than new. Very difficult to tell using the white paper towel test.

Has anyone thought about installing a cooler on the differential? It would require an auxiliary pump also, I assume.

I noticed the other day that on my wife's Y33 2000 Q45 both front fender wells are vented in front. Immediately thought of adding an oil cooler as oil capacity in the VH series of engine is barely adequate in my unlearned estimation. But I can't even recall anyone who has even added a transmission cooler to this series of Q45. Hmmm.... Did I miss something with my initial concentration on the G50? Anyone ever added an oil cooler to any series of Q45?__________________Brian1995 Q45 & Q45t & 2000 Q45

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[Q45tech]

Oil pan temperature is a function of coolant temperature. As long as the coolant doesn't exceed 190F at outlet of heads the oil will be in control...........with synthetic formulations.

Many of the newer transmission versions have improved seals of different materials than the old phenolic paper. Same with glue better able to stand the heat.

But you never know whats happening till you measure it.

[szh]

10F sounds about right as Mobil 1 engine oil will do the same for oil pan temperature........and a premium diff fluid will lower that unit even more.

What is a good premium differential oil?Quote » racks are cheap compared to transmissions or differentials. [/quote] In comparison, yes, but still not that low! I had a Q45 steering rack changed at a cost of $950 (for a new rack including the installation at the dealer, a refurbished one would have been $750). Fortunately, the extended warranty covered most of the cost. And, of course, a non-dealer install would probably be lower - what does T3 charge for this?

Z

[PalmerWMD]

What is a good premium differential oil? Z

MOBIL1 GL-5.Redline also makes a very good GL5.

Fred..

[szh]

Thanks, Fred!

Z

[elwesso]

Valvoline synpower GL5 is also a good choice........

While we're talking about transmission coolers, do you think its better to completely bypass the stock heat exchanger or put the cooler downstream of it..... ?

[PalmerWMD]

Yes completely bypass.

Fred..

[maxnix]

Well, I am in the experimental group here, for four reasons.

1.) When I went to replace the fluid at 57k, after only a drain and refill at 52k, the fluid was in near perfect condition. Subsequent pan drop confirmed this with a very light coating of material on the pan. The car previously was used primarily for summer trips to Colorado and to the Gulf Coast from Austin. Obviously, the new OEM heat exchanger design has worked well for the type of previous use the car had and it now doesn't get driven in the summers anymore.

2.) The OEM external filter has obviously worked so far, so I wanted to retain it in the circuit. While the duty cycle for this part is unkown, Joe says the only ones he sells are requested by customers, not by technicians because of part failures.

3.) By utilizing the hold down bolts (replaced one with a longer version) for the lower half of the airbox, the B&M cooler mounts beautifully in front of the louvers in the front driver's side wheel well. It is out of harms's way here and receives excellent airflow without adding any heated air to the front end cooling flow.

4.) It is a simple hook-up to route the return line to the cooler before it goes back to the transmission with merely the addition of a hose from the out put of the cooler.

Finally, I used a 70268 because of the recommendation of the board. On my next one, I will use a 70264 because of its additional cooling capacity and better fit.

If I see any indications of less favorable performance, I can change it to by-pass the OEM heat exchangers in the future. If I were to judge by the fluid condition alone, I probably would not have considered even adding the cooler.

I'll keep the board informed, but this car only goes about 4K a year. Soon, it will be the lowest mileage one instead of the highest.__________________Brian1995 Q45 & Q45t & 2000 Q45

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[Q45tech]

The only way to know if a filter is dirty [blocked /restricting flow] other than inaccurately weighing it is to install differential pressure meters on both sides of the unit looking for minute changes [differences in pressure].Much the same way as one checks a fuel filter........a replacement interval works wellPretty obvious why technicans don't spend hours setting up and testing a simple inexpensive part. They must budget their time to yield the Greatest gain.........they must bill 10 hours per day and that translates to $1000 in parts at retail that need to be changed to make their paycheck.

The service manager gets hell if parts are not replaced afterall they are paid for and in inventory........nothing like a few transmissions to brighten a day!............need to sell 70 filters to equal one transmission.

Don't assume that dealer technicans are that knowlegable on engineering matters like life extension..........they are not paid by how much they save you.........and if things don't fail they are out of a job.............luckily the factory cost cutting assures that doesn't happen.

[maxnix]

Why I think I will be another customer of Joe's who replaces that external filter next fluid exchange, even though the fluid was almost pristine as new. Does T-3 routinely replace it?__________________Brian1995 Q45 & Q45t & 2000 Q45

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[Q45tech]

We have replaced a few but don't keep them in stock.

Even we prefer a transmission change to a flush/or a pan drop.........takes over 24 flushes to equal the gross of a transmission change. The transmission change work is 4 times faster also.

Don't confuse my comments here with a successful business.

Owners get what they ask and pay for at a business. Being proactive [unless you know the customer well] tends to sound pushy and they think you are padding because they don't understand.

Special [non standard services --- things dealers don't do] are best prediscussed and parts supplied by owners.

[elwesso]

Is there a bigger cooler available rather than the 70268...... I plan on putting mine in the active cooler location...... Thats just where I want it, I dont want to put it in between the rad and condenser.....

Also, on summit racing, there is a kit available for an external transmission filter...... The kit is only 26 (comes with a base, a filter, and fittings), and you replace it with a screw on type filter...... I have the OEM filter still on, so Id assume its shot..........

Worth it???

[Q451990]

I plan on putting mine in the active cooler location...... Thats just where I want it, I dont want to put it in between the rad and condenser.....

I spent some time looking at that and couldn't come up with a good size cooler to work there. You also need an auxilary fan (already there in the other location) and ducting. As much as I like the idea, the simplicity of the "normal" location won out - not to mention that it seems to work well there.

The way I do things, if it's going to take some time and enginering, it'll get put off, so the benefit of having it done earlier (and saving the transmission from heat sooner) was worth it.

All of that said, if you do get it in the "A" slot, please post pictures! I think finding a doner "A" car for the auxilary fan, brackets, and duct that runs from the bumper vent to the cooler, and then substituting a new transmission cooler of a similar size would be the best way to approach it. I'd love to see how it works!

Heath

[maxnix]

I spent some time looking at that and couldn't come up with a good size cooler to work there.

While the 70268 works fine, the 70264 would be better and has a higher cooling capacity.

You also need an auxilary fan (already there in the other location) and ducting.

If idling in city traffic in the Texas summer, I would consider the powered fan model. Haven't checked to see how it would fit. I think ducting is unnecessary in this location as there is plenty of air flow at even low speeds.

As much as I like the idea, the simplicity of the "normal" location won out - not to mention that it seems to work well there.

This location is much more simple on the later Q45 with twin OEM heat exchangers as the hose modifications are almost nil when retaining the OEM external filter and heat exchangers in the coolant path. If I hadn't seen how new the old fluid looked, I never would have considered this solution.

The way I do things, if it's going to take some time and enginering, it'll get put off, so the benefit of having it done earlier (and saving the transmission from heat sooner) was worth it.

This is about a 30 minute job once one knows what needs to be done.

I think finding a donor "A" car for the auxilary fan, brackets, and duct that runs from the bumper vent to the cooler, and then substituting a new transmission cooler of a similar size would be the best way to approach it. I'd love to see how it works!

An interesting idea! I'll have to look at an a model sometime. Maybe the service manual has a diagram.

I promise to take pictures when I install the 70264 on my Q45t in Seattle.

__________________Brian1995 Q45 & Q45t & 2000 Q45

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[elwesso]

So there is a cooler that comes with a fan??? That may not be a bad idea..... You could then disable it during the winter when it gets really cold (here in indiana)......

Ill take a look at my service manual when i get a chance.......

I looked at advance auto parts, and they have quite a selection of transmission coolers....... I may just stop by and tell them what size I need and go from there!!!!

[PalmerWMD]

1)I plan on putting mine in the active cooler location...... Thats just where I want it, I dont want to put it in between the rad and condenser.....2)have the OEM filter still on, so Id assume its shot..........

1) the biggest coolers fit between rad an condensor, the active cooler location is a good one but uses smallere coolers2)why not put in a fresh oem?cheap.Also mine is out altogether; i like flow and with the higher flushing frequency than the public, it is likely not neccessary for us.

Another reason for a by pass cooler is u avoid the clogging problem in the heat exchanger all together.

Fred..

[elwesso]

So I guess Ill just rip the external filter out and forget about it.....

[maxnix]

So I guess Ill just rip the external filter out and forget about it.....

The external filter was added to prevent particles from clogging the heat exchangers. Read the relevant TSB on cleaning the heat exchangers. The heat exchanger flushing procedure is not required for the G50 with the external ATF filter.__________________Brian1995 Q45 & Q45t & 2000 Q45

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[oxs1]

where can i find the transmissions coolers you guys are talking about? I need one also.

[DAEDALUS]

http://www.summitracing.com

Look for B&M 70268.