Transaxle Pump

[L.R.S.]

I just added the weddle pump to my trans when it got rebuilt. Everyone I spoke to with high horsepower cars has the pump turn on with the ignition. That is how I did mine as well. It’s noisy when it’s cold but I can’t hear it over the fuel pump once it warms up, and I know it’s pumping lube at all times.

Pumping the diff under temp will prematurely wear out the pump. Best is to have it on a thermo switch or on a dash switch you turn on manually after driving for a while and heating up the fluid.

 

[Justgetnby]

Pumping the diff under temp will prematurely wear out the pump. Best is to have it on a thermo switch or on a dash switch you turn on manually after driving for a while and heating up the fluid.

Correct. But a $400 pump cost much less than a trans rebuild, as I know you are aware.

By having it come on with the ignition it’s fool proof. No forgetting to turn it on and most of the time they never get warm enough to turn on with a 150 degree temp switch.

I can pay for 20 pumps for what my trans cost to fix..

 

[Fullthrottleguy]

Correct. But a $400 pump cost much less than a trans rebuild, as I know you are aware.

By having it come on with the ignition it’s fool proof. No forgetting to turn it on and most of the time they never get warm enough to turn on with a 150 degree temp switch.

I can pay for 20 pumps for what my trans cost to fix..

I appreciate where you are coming from, 

But, let me give you the opposite opinion---- when your pump fails on a cold day trying its best to pump cold fluid  - you will not hear it fail over your fuel pump and probably won't notice its failed for the next trip because you get used to the sound

The trans fluid will get to 150 Very quickly if you are measuring it at the fill hole. under that temp moving fluid around does little if anything to help the trans as the fluid will not be "falling away" it climbs when cold. 

Having the fan come on the cooler at 180 gives allows the pump to stay on (if thermal switch is set at 150) and still keep fluid at a proper temp.  

Thats the way the manufacturers recommend it   - and they seem to have the experience. 

Pump or no pump Trans bearings (the main thing to fail) Fail the same as any other bearing - you put severe load on them when they are cold - this is true with gears as well although once they "work harden" this is less a problem I am told

As I have reminded many times ...Just like your engine, the best thing to make your trans Live a long life beside a good break in  and changing fluid often is after you let the engine come to temp before a ride  you Putt the car around camp and let the trans come up to temp instead of the "baller method" of hammering on it right out of camp  - long wheelie and 100' roosts ...

 

[lincster]

Agreed on just putt putting the car around when the tranny is cold.

Our morning rides it is 45 outside sometimes.

I will drive my car around camp for 10-15 mins before we actually head out in the dunes.

I'm not a baller so I don't worry about 100' roosts. 

 

[Justgetnby]

I appreciate where you are coming from, 

But, let me give you the opposite opinion---- when your pump fails on a cold day trying its best to pump cold fluid  - you will not hear it fail over your fuel pump and probably won't notice its failed for the next trip because you get used to the sound

The trans fluid will get to 150 Very quickly if you are measuring it at the fill hole. under that temp moving fluid around does little if anything to help the trans as the fluid will not be "falling away" it climbs when cold. 

Having the fan come on the cooler at 180 gives allows the pump to stay on (if thermal switch is set at 150) and still keep fluid at a proper temp.  

Thats the way the manufacturers recommend it   - and they seem to have the experience. 

Pump or no pump Trans bearings (the main thing to fail) Fail the same as any other bearing - you put severe load on them when they are cold - this is true with gears as well although once they "work harden" this is less a problem I am told

As I have reminded many times ...Just like your engine, the best thing to make your trans Live a long life beside a good break in  and changing fluid often is after you let the engine come to temp before a ride  you Putt the car around camp and let the trans come up to temp instead of the "baller method" of hammering on it right out of camp  - long wheelie and 100' roosts ...

I absolutely see where you are coming from. And that may be the case. I do listen for my pump on cold startups but who knows how long I’ll do that before forgetting..

When I spoke with Sean at Weddle about this, he was uncertain if even at 150 the pump would turn on for most duners. Beings most rides are short between stops they likely won’t get all that hot. In fact I have a trans temp gauge on my display and have yet to see 150 from my trans. And I was just in Idaho last week for the races in 85 degree weather and long dune runs..

so that tells me that most people that have that switch never have the pump come on, unless they are running for long periods of time, say the duners diner run..

Again I think the switch is the best thing. However 150 is too high. Make it 100 and I’d be on board. 

 

[Fullthrottleguy]

I absolutely see where you are coming from. And that may be the case. I do listen for my pump on cold startups but who knows how long I’ll do that before forgetting..

When I spoke with Sean at Weddle about this, he was uncertain if even at 150 the pump would turn on for most duners. Beings most rides are short between stops they likely won’t get all that hot. In fact I have a trans temp gauge on my display and have yet to see 150 from my trans. And I was just in Idaho last week for the races in 85 degree weather and long dune runs..

so that tells me that most people that have that switch never have the pump come on, unless they are running for long periods of time, say the duners diner run..

Again I think the switch is the best thing. However 150 is too high. Make it 100 and I’d be on board. 

 150 degrees Fahrenheit is pretty low  - think how fast your engine gets there. We always hit 150in the trans in about 10 minutes of Duning pretty consistently, but we do some fast runs, no matter how cool it is outside. I log the Trans temp and engine oil temp in the Holley ECU. You might have a bad sensor.  100 degrees is still really hard on the pump. 

But if the way you are doing it works for you stick with it!

 

[Kevin]

I absolutely see where you are coming from. And that may be the case. I do listen for my pump on cold startups but who knows how long I’ll do that before forgetting..

When I spoke with Sean at Weddle about this, he was uncertain if even at 150 the pump would turn on for most duners. Beings most rides are short between stops they likely won’t get all that hot. In fact I have a trans temp gauge on my display and have yet to see 150 from my trans. And I was just in Idaho last week for the races in 85 degree weather and long dune runs..

so that tells me that most people that have that switch never have the pump come on, unless they are running for long periods of time, say the duners diner run..

Again I think the switch is the best thing. However 150 is too high. Make it 100 and I’d be on board. 

i can say that for sure they would kick on at 150 if not higher. granted my setup is different since i use just a quick change diff mated to a powerglide, but my diff temps were typically near the upper 250 range after hard runs and ran consistantly in the 200-15 range under normal cruising. needless to say im adding a pump and cooler to it.. so id imagine adding a gear stack into the mix the temps would easily get up there inside that case.

 

[lincster]

I have taken an IR temp handheld gauge to my trans after a run.  180-200 is not uncommon.

That is on a normal dune run for us.

For comparison, CV body measures 210-220.

 

[Justgetnby]

 150 degrees Fahrenheit is pretty low  - think how fast your engine gets there. We always hit 150in the trans in about 10 minutes of Duning pretty consistently, but we do some fast runs, no matter how cool it is outside. I log the Trans temp and engine oil temp in the Holley ECU. You might have a bad sensor.  100 degrees is still really hard on the pump. 

But if the way you are doing it works for you stick with it!

I very well could have a bad sensor then. It’s all new but it’s never shown it’s got hot. 

 

[Justgetnby]

I have taken an IR temp handheld gauge to my trans after a run.  180-200 is not uncommon.

That is on a normal dune run for us.

For comparison, CV body measures 210-220.

I’ve done the same and the highest I’ve seen is 110. That’s in Utah on the big hill but those runs arent long. ** I changed this when I realized I did this in Utah and not Idaho dunes. I will try and remember to do it in Idaho see what happens.**

Op, get the gear drive  pump and wire it how you seem fit. It will help and hopefully give you much longer rebuild intervals with your trans. 

 

[L.R.S.]

Become of a lack of ports on my Albins my trans temp sender is just outside the diff. It T's into the pump suction line at the bottom/side of the diff and I've found when I see 140° on the temp gauge (Racepak dash) I can manually turn the pump on and watch the temp gauge quickly climb to 160-170°. We also do hard dune runs and my car is 3500lbs. I also drive it like an azzhole but mostly because I'm trying to keep up with 4-5 Funco's. 

 

[Sean@Weddle]

Trans Mainshaft Bearings: circulating oil is the best solution to extending mainshaft bearing life in any MD, S4/S5, S4D/S5D transaxle. Bearing is in front of trans and high out of the oil, what happens when you are accelerating up hill? (Hint: oil runs to back of trans). Pump keeps oiling that bearing in all instances.

Temp Switch: We used to have a 125º switch, had more pumps come back with burned up motors from oil too cold. Pump motor manufacture told us to start pumps with less load on them. Now we use 150º switches. Not ideal, but it's what seems to work.

Warm ups: Always best to warm up engine and trans with some light duty driving before driving hard. Engines and transmissions are designed to be operated at 180º-220º. Housing bores (bearings, pistons, etc) are tight when running at room temp. They loosen up at operating temps for best operation and least resistance. 

 

[HTElectrical]

@Sean@Weddle  Where is the best location for the oil lines to lubricate the bearings, and gears?  Md4-2D

 

[Sean@Weddle]

I only care about the one on top at the very front of the trans. This hits directly on top of 4th gear and splashes the mainshaft bearing. No need for a split as the pictures show. Get oil to the front of the trans/mainshaft bearing. 

 

[Mike E]

Trans Mainshaft Bearings: circulating oil is the best solution to extending mainshaft bearing life in any MD, S4/S5, S4D/S5D transaxle. Bearing is in front of trans and high out of the oil, what happens when you are accelerating up hill? (Hint: oil runs to back of trans). Pump keeps oiling that bearing in all instances.

Temp Switch: We used to have a 125º switch, had more pumps come back with burned up motors from oil too cold. Pump motor manufacture told us to start pumps with less load on them. Now we use 150º switches. Not ideal, but it's what seems to work.

Warm ups: Always best to warm up engine and trans with some light duty driving before driving hard. Engines and transmissions are designed to be operated at 180º-220º. Housing bores (bearings, pistons, etc) are tight when running at room temp. They loosen up at operating temps for best operation and least resistance. 

Where on an S4 are you placing the temp switch? I have been running a pump but wired to a manual switch and I have forgotten to turn it on so a temp switch would ground a relay and turn the pump on without me having to remember. 

 

[Sean@Weddle]

Where on an S4 are you placing the temp switch? I have been running a pump but wired to a manual switch and I have forgotten to turn it on so a temp switch would ground a relay and turn the pump on without me having to remember. 

Universal location would be in the hole next the passenger CV joint (opposite side of brass bolt on driver side).

New Weddle cases use 3/4" straight fittings for all holes/fittings. You can install the temp switch in the lower hole on drivers side, just in front of the bell housing chassis mount. (Old cases used 3/8" NPT fittings down low, hence the universe location for 3/4" straight threads next to the CV joint)

 

[Fullthrottleguy]

Universal location would be in the hole next the passenger CV joint (opposite side of brass bolt on driver side).

New Weddle cases use 3/4" straight fittings for all holes/fittings. You can install the temp switch in the lower hole on drivers side, just in front of the bell housing chassis mount. (Old cases used 3/8" NPT fittings down low, hence the universe location for 3/4" straight threads next to the CV joint)

Thats exactly where I put temp switch on all the cars I do.    Weddle Part #  9-Switch 34 is the one I use, add a weatherpak or DT connector  so you can easily remove the switch to fill and its easy

 

[Mike E]

Universal location would be in the hole next the passenger CV joint (opposite side of brass bolt on driver side).

New Weddle cases use 3/4" straight fittings for all holes/fittings. You can install the temp switch in the lower hole on drivers side, just in front of the bell housing chassis mount. (Old cases used 3/8" NPT fittings down low, hence the universe location for 3/4" straight threads next to the CV joint)

Thank you. I'll get one ordered up and in there