Trans Temp & Tach installed

[bhayden]

As part of a batch of preventive maintainance I had our mechanic install a transmission temperature gage in our 2000 GMC Safari van. I did quite a bit of searching to come up with gages that would fit and "look right" in the van.

Really the only option for the van was to go with the A pillar mount. This set the size of the gages to the "mini" 2-1/6 inch variety. The pods came with either two or three gage clusters so part of the decision was what did I want besides the temp gage. I opted for the tach since I really wanted to know where our little 4.3L V6 was in the power band. As it turns out transmission temp isn't one of the most common gages and tachometer selection in the 2-1/16 inch size is a little limited. I came up with the Auto-Meter Z-series short sweep electric transmission temp and their so called "in dash" low rev tach . This gave me a good useful range for both gages. No sense in having an 8,000 rpm tach in six cylinder van and likewise the other option with the trans temp was 140-280.

The end result came out pretty good. I'm glad we left the pod black and didn't try to color match (i.e. mismatch) with vinyl paint:

No trailer pulling yet and it's been in the low 50's here most of the time we've been driving. Steady state temp on the tranny seems to be 130-140. When I had the work done the mechanic install a deeper pan and we flushed and refilled with Royal Purple synthetic ATF. Supposedly that should drop the transmission temp under all conditions. I didn't have the gage before going to the synthetic fluid so I can't be sure. I knew the synthetics were better at resisting heat which was the main reason I wanted it installed. What I found out with a little research is that one of the big advantages of synthetic is low temperature performance. Turns out to me much less viscous at lower temperatures which results in better performance (less power loss than trying to pump molasses throught the tiny valves in the throttle body) yet still provide better protection. Good thing since it takes about 15 minutes of driving before the transmission temp gage moves at all. The sending unit is in the sump. From what I read there is enough mixing that that gives you a good reading of the overall temperature. It certainly was the easy route since the aftermarket pan had a threaded drain hole that accepts the sending unit. I may end up moving it to a location that gives more immediate feedback but I'll wait until we have more experience with the trailer and warmer weather.

As for the tach we're running about 1400 rpm on the freeway in OD and it pops up to about 2,200 when I drop down to 3rd with the 3.7:1 ratio. Haven't played much with it yet but already I feel much better about leaving it in 3rd for all trailer towing. Actually it's now painfully apparent why towing in OD with this set-up is a really bad idea .

-Bernie

[GlenCoombe]

Nice clean install, now all you need is the big bad tail pipe to make some noise. (kidding, just kidding)
Noorskog has some very nice digital guages. I used their digital units for coolant temp and tackometer on my old coach. Got mine at Summitracing.com .

[moosetags]

Thanx for the info Bernie. I am considering switching to synthetic ATF. Please keep us posted on your results.

[Silvertwinkie]

I too did this when I towed with our sedan. The trans temp is a crucial piece of info to have while on the road. It's hard to understand (outside of manufac costs) why rate a vehicle to tow 5k+ and not have one installed as part of a tow package.

If this van has the 4L60e trans, you might also look at the torque converter cover cooler. It has a "ram air" type scoop to allow cooler air to pass over the front of the trans, rather than keep it totally closed with heat buildup.

It's made by a company called Neal and you can get one here:

http://www.clearimageautomotive.com/...Drivetrain.htm

[peegreen]

That gage pod on the 'A' pillar looks great. I'd like to add that to the Excursion for turbo boost, exhaust gas temp and something else to look at and get concerned over when the indication just looks a little out of normal. Information overload is my goal. I'll have my kids take hourly logs, evaluate the trends and red circle out of specs. My original brake controller just had a green LED that turned red when the brakes were applied. I didn't want any digital readout like on the Prodigy - I was afraid it would be telling me something was wrong, and I really didn't want to know. Now with the newer rig and TV, went with the Prodigy so I would have more stuff to look at besides the road and the big rigs pulling along side me. I'm glad my XM receiver came with a remote.

[bhayden]

OK, first time out pulling the trailer since installing the gages, deep pan and synthetic tranny fluid. Since I had the work done last fall I've monitored temperatures during normal driving over the winter which included some cold weather driving (by NW standards ) and many trips up into the mountains.

Since I didn't have the temp gage before switching to synthetic fluid and a deep pan I don't know how much effect this had over the stock configureation. However I can tell you that I rarely see the transmission temperature (measured at the sump) go over 150 degrees. Most of the time it's around 125-135 and for short trips (i.e. less than 20 minutes) the gage barely moves. From what I've read one of the big advantages of synthetic is cold weather performance as well as resistance to heat. That coupled with the fact I'm measuring sump temperature doesn't have me too concerned about the lower than 180 degrees reading I've seen reported for "normal".

So, pulling the trailer; on flat ground with the outside air temp in the high 50's to mid 60's the transmission temp gage was reading around 150 or about 15 degrees warmer than when not towing. That was at 60mph with the transmission left in 3rd (no OD). Going over Snoqualmie Pass the Safari van was able to pull most of the grades without down shifting and the temp would rise to about 165-180. On the steeper grades the transmission would downshift to 2nd and I'd hold the speed at ~52mph (3200 rpm). Cresting the summit I saw a peak of 200-205 degrees and that was for less than a minute. Not bad but it was 50 degrees at the top of the pass. Pretty much the same thing pulling the big grade up and over Manastash and Umtanum Ridge where the air temps were up around 65 degrees.

In normal driving the trans temp seems to go up pretty much in line with the ambient temperature so if I'm trying to do this in the middle of summer it could be in the 90s. That would push the tranny temp up close to 250. It would likely be hotter than that since the engine coolant would undoubtedly be well above the 180-190 it stayed at during this mild weather excursion. In fact the 180-190 is the coolant temp in the block which is controlled by the thermostat. I suspect the actual radiator temperature is down in the 150 degree range I'm seeing for the trans temp. Anyway, while 250 degress might not fry the synthetic fluid it's a little to hot for comfort.

To cut to the chase, I'm going to install an external cooler. I know, I know... I can hear you all saying "I told you so" . The unit I'm looking at getting is the B&M SuperCooler 70264 One thing that looks attractive is the cool fluid bypass (aka Low Pressure Drop mechanism). This looks to be a feature of plate type coolers in general and sounds useful since 99% of the time extra cooling is not needed.

One question I have is when I get the new cooler installed should I have the mechanic move the temperature sensor? I've read the various theories on this. Having it at the exit will give you a higher temperature and quicker response. However, it may not tell you much about how your cooler is operating; especially with the bypass feature of a plate type cooler. If I leave it where it is I'll have a better basis of comparison. However I never really thought the sump was the best place to monitor. It was just the easiest since the sump had a drain fitting that could be utilized. Now that I'll be breaking into the stock "plumbing" anyway I'm leaning toward temperature sensing on the return line from the cooler.


-Bernie

[SilverToy]

Bernie -

Just to let you know that I am thinking of doing the same cooler add on. Minor twist to my set-up as I already have a factory cooler but given some of the grades I pull, I think that it is inadequate. As such, reading your post is most interesting! Be sure to post your progress (photos PLEASE!!!) with any/all location mounting info, the temp sensor question solution, as well as any info on where the factory system was modified (ie where the lines were added). Also, sorry if I missed the info, but what is your TV/TT combo?

Thanks for the postings, and keep it coming!

Axel
SilverToy

On edit -Sorry found the TV info in your 1st post. Duh. So much for 'effective' skimming.... Sigh.

[bhayden]

So, finally got around to ordering the trans cooler. Trans temp Wednesday just driving in traffic when it was 102F outside was hovering around 200F and peaked at 210F. Front & rear A/C on max of course . Anyway, on the advise of my radiator and A/C guy I bought the B&M Co 70268 Supercooler Oil Cooler The difference between this and the 70264 is the thickness is 3/4" instead of 1.5". There's already a full width radiator for the A/C infront of the engine radiator and even if the thicker unit would fit behind the grill it might not cool any better since there would be such a high restriction most of the air would want to flow through the other side. Anyway, the mechanic said the standard unit would be more than adaquate for my rig and the HD cooler was only warranted for 1 ton and larger trucks pulling near maximum loads.

As soon as I have it installed I'll report back.

[Wabbiteer]

Bad link - *ttp://b&m%20co%2070268%20supercooler%20oil%20cooler/; the * is to keep vbulletin from reparsing it even worse...

[bhayden]

Works fine for me but then here's a copy and paste of the link location from my post:

http://b&m%20co%2070268%20supercooler%20oil%20cooler/

That's certainly a strange looking URL and when I paste it into my browser it translates to the following page:

Amazon.com: B&M Co 70268 Supercooler Oil Cooler: Automotive

Sorry, must be some sort of caching that my Firefox session does? -Bernie

PS. Can't edit my own post after there's been a reply or I'd have just fix it.

[Wabbiteer]

Thank you for the Amazon link, and note the self-edit option expires after 30 minutes or some such arbitrary time period - one of the original administrators must've been bit by an editor as a child...

Without a side-by-side comparison of the original type versus the replacement synthetic merely adding synthetic may adversely alter your driving experience. When I changed the ATF fluid in my F-150 I was hesitant to pay the premium for the Ford Motorcraft synthetic (?) so I went with another synthetic and found when pouring it in that it was a heavier bodied fluid that changed the transmission performance into more of a 'tractor' instead of 'highway' vehicle; very, very good low RPM tourqe transfer but it kind of bogs down with higher RPM as compared to OEM fluid. Now after 40K miles I will be changing it again soon and will put the OEM fluid back in - and taking compressed air to blow out the cooler and cooler lines to purge as much old fluid out as I can...

[3Ms75Argosy]

Bernie - I think that the 3/4 inch plate is the one I ordered from Summit Racing when I had the V8 Astro. I remember too thinking about placement... I was concerned about the AC and radiator cooling. In my earllier (non-current flat nose '89) model, there was space below the bumper and behind a spoiler vent that I put it. I also did not have the radiator "cool" the tranny fluid... i.e., I eliminated the stock "tranny cooler/heater". My reasoning was that the engine would be running hotter, so it would be putting heat INTO the fluid at top temps. I was worried about it running too cool... but sold the van before I even got to a winter with it.

I really wanted to mount it under the floor, but couldn't find a suitable place to mount it too. I think the exit line is the best place to mount the guage sensor too... although, if I think about it, does the tranny p/u from the pan? I'd have to check my old manuals and figure that out. Wherever it get's it's fluid from is probably the best place.

I did put synthic fluid into the pumpkin after I lost the carrier bearings... ouch, that was expensive! Randy's ring and pinion in Everett (GREAT place by the way) did the repair and lowered my final drive to 4.11 for me, at half the price the dealer's were charging for just repairing the bearing. I'd suggest the oil here to help out the rear end. I guess it's a weak link from what I've read about Astros.

Who is your mechanic? I lost my favorite corner garage here ... the owner sold it to the city for a new fire station. :<
Marc

[bhayden]

When we were into the transmission we ended up going whole hog and had them (Kirkland Transmission) go through the transfer case and the rear end. After about 20k on the fluid I had my mechanic (Jeff at IPM in Redmond) replace the transmission fluid with synthetic. He used Royal Purple which seems to be fine although I'd prefer Amzoil. The biggest difference I noticed is that cold weather driveability was greatly improved. I had a chance to test this in near 0F temperatures up skiing! At about 30k after the driveline rebuild I had him change out the fluid in the transfercase and the front and rear differentials with synthetic. He used Valvoline for this. That's working just fine (after the limited slip additive was put in) and we noticed about 1-2mph gas milage improvement on the freeway or about 1/2mpg improvement when towing.

I'm going to have my AC and radiator guy do the trans cooler install. I'll follow his recommendation and the B&M instructions as far as putting the cooler in line with the stock cooler and in front of the radiator. Supposedly that makes for the most efficient cooling system. Even going over the pass or the big grade from Ellensberg to Yakima the radiator temp is virtually always at 190-200F and as you say in cold weather the faster warmup is a benifit.

Don't know if there's a place down lower that would get air from the front air damn but my concern with that is that unless I add an additional fan it would get no airflow when stuck in stop and go traffic and when backing the trailer. Of course with the damn electric fans usually set to only turn on AFTER the engine gets too hot I'm not sure I can count on that for airflow anyway!

-Bernie

[SilverToy]

Bernie -

Followed your thread with great interest, as I too was concerned with higher than I liked trans temps on my TV. TV is an '01 2500 HD Burb with the 6L & 4x4.

I debated with the trans cooler vs the fan vs additional cooling vents/cowls and etc... Finally decided to go with an electric fan with a manual on/off switch. This allows ME to control the on/off activation. I do have the factory trans temp gauge on my TV.

I decided to go this route as it allows me to anticipate higher trans temps when I hit grades, use the tow haul, am sitting in traffic, using reverse, NO airflow situations, and the like.

Having just done 2100 miles with SilverToy in tow ('92 34'er) over some serious grades, I can report that even at 50+MPH, the fan with my control, DOES offer significant cooling advantage!

To the tune of about 20+ degrees cooler.

I know since I pulled the same road/grades in a previous trip ( charted my temps vs. mile marker) and this time I had WAY less stress on me, AND on the trans.

I knew, when hitting grades where the TV kicked down, or I shifted down, that it was time to cut the fan on, and it did it's job and added additional airflow to the factory cooler. Did the trick. Running the wires wasn't that tricky. Used a standard 'off the shelf' item at Yearwood Speed and Custom. 2100CFM as I recall.... Gotta watch puller vs. pusher though....

Hope this info helps someone else out there....!!!! If there additonal questions, I'm happy to help!

Axel
SilverToy

[Kevbo10]

Originally Posted by SilverToy

Bernie -

Followed your thread with great interest, as I too was concerned with higher than I liked trans temps on my TV. TV is an '01 2500 HD Burb with the 6L & 4x4. any questions, I'm happy to help! Axel SilverToy

mr axel,

fair warning... were coming to NM to watch balloooons. hide everything. well, the other 'streams are coming to watch, i'm coming to yak, yak, yak...

kevin

[SilverToy]

Kevbo -

Check your PM's since I sent you one re: BFR. I won't be there - sadly! PM explained it all - certainly more boring drivel (to the average ASF reader) that I care to subject them to.... now you on the other hand, well, your expected to put up with it since we rallyed together with such fun, hilarity, and, well, Max. He still talks about you ALL THE TIME WHEN WE GO VISIT THE AS!

Again, sorry for the complete breakdown around the brevity issue, but it just needed some more than the usual.

Chech that PM

Axel
SilverToy

[bhayden]

Well, got the B&M SuperCooler installed last week and had our first chance to tow with it this weekend. Since we've had it installed temperatures here in Seattle have been unseasonably mild with highs only in the mid 70's so it's not really been an acid test but the results are still amazing.

Just driving around town transmission temperature is lower by about 25 degrees. That is with the outside temperature in the 70s the gage is reading ~125 at the sump. I might worry about that being too cool except the sythetic fluid extends the working range both on the hot and cold side. The cold weather performance was demonstrated last winter when the temperature up at the ski hill hit 10F for the high. Stop and go traffic shows even better performance with the SuperCooler. What would have sent tranny temps up around 180-200 are now peaking at around 150.

Trailer towing showed the biggest difference pre/post cooler installation. Admittedly it wasn't that hot this weekend and Snoqualmie Pass isn't a monumental grade but the direct comparison with a trip earlier in the year leads me to believe the "reserve capacity" provided by the low temperature bypass design of the SuperCooler really does work. Last spring we pulled the Pass with a lighter load and the temperature at the summit was 40 degrees. The tranny temp peaked at ~200F. This trip the outside temperature at the Summit was 60 degrees and the temperature peaked at ~160F.

Oh, one other thing I noticed is that trailering on the flats where we'd previously seen the transmission run ~25 degrees warmer than normal we're now seeing virtually the same temperature as when not towing.

I'll give the B&M SuperCooler a two thumbs up -Bernie