[Dysfunctional]

My trans temps have gone WAY up in the last two weeks. Prior to this, the highest temp I've ever seen was 180* driving like a PRICK on a 118* day over the crooked and steep mountain road I drive daily. Today I hit 230* in the morning with outside temps in the 50's oke:

Tonight I came home, hooked up a snap-on MODIS I'm borrowing from a friend and went for a test drive. Trans temps with the scanner are +/- 10* of what my autometer gauge says, I even got it up to 240* with ambient in the high 90's. You can monitor alot with this scanner, but I just locked in trans temp, TCC%, TorqueConverterClutch (on/off) and gear. When I LUGGED it on hills with TC locked in 3rd, TCC% shows 100%. A downshift, TCC% drops to about 60% momentarily (this seems ok). If I climb a grade with 2nd gear manually selected, the TC never locks according to the scanner (TCC shows OFF the entire time to any MPH) and my temps rise FAST.

IMO something is wrong... My temps are sky high out of nowhere. So the other weekend I bypassed the bypass valve on the trans by removing it and adding fittings to adapt back to the threads in the trans. After that temps seemed lower and stayed in check a few days.

When I got back tonight and my trans temp was 240*!!! I started feeling the cooler lines and I didn't not burn myself. Seems to me with fluid that hot I should have 2nd degree burns on my hands right?

Tomorrow I'm going to my friends shop to have the transmission flushed with a machine, 10 times if necessary.

Short version of this babble... I'm thinking I have a blockage...? :swordfight:

 

[bigblockhorse]

sounds like a blockage someplace, you can flow test the deal to find where it is.

If its in fact blocked eliminating the bypass is gonna smoke the unit, in a hurry.

You can unhook the cooler lines and blow air back through it to see if any debris comes out of the coolers.

 

[Dysfunctional]

I found the blockage. I had debris stuck in the OTW cooler. I did a flow test and only got about a 1/4 of a quart in 15seconds from the return line. So I popped all my lines and started blowing them out with air. When I blew air through the OTW cooler circuit (opposite of the fluid flow), I got a bunch of small brown hard flake lookin crap. I'm assuming this is TC clutch?

Prior to finding the blockage... I flushed the entire fluid system twice, dropped the pan and installed a new filter. Temps got better, but not back to *normal*. I will get the fluid bypass tube back on there, but I had to eliminate that as a possible cause.

I'm trying to hold off untill later this year/early next year for a bad mo-fo trans. I'm looking to pick up a decent (not the best) TC right now. I'm going to drop the trans, do the rest of the tugger kit (front pump mods, snap rings), Lockup on/off valve and install a new TC. Then cry myself to sleep thinking I'll be re-doing this stuff soon. Sound like a plan? :hehe:

My truck drove perfectly fine, no shudder or slipping felt. If it weren't for having gauges.... I'd be clueless. oke:

 

[Transman]

Sorry, but it is best to leave the bypass off! This is the cause of most tranning overheating problems. The bypass was used to heat the fluid on units without rad cooling and cheaper to leave in instead of removing. If you had that much converter clutch in the cooler you will have failure soon.

Just to help,if you plan on installing the other parts of the transgo kit you need a better snapring then the one furnished in the kit.This the second design and will still pop out! If you use manuel 1 or 2 on decell then install the tugger. If you do not this part of the kit does nothing for you.

Transman

 

[bigrpowr]

dang thats some good info!!

 

[gregrob]

Sorry, but it is best to leave the bypass off! This is the cause of most tranning overheating problems. The bypass was used to heat the fluid on units without rad cooling and cheaper to leave in instead of removing. If you had that much converter clutch in the cooler you will have failure soon.

Just to help,if you plan on installing the other parts of the transgo kit you need a better snapring then the one furnished in the kit.This the second design and will still pop out! If you use manuel 1 or 2 on decell then install the tugger. If you do not this part of the kit does nothing for you.

Transman

Transman, what about someone in cold climates? Could not having the bypass cause a starvation problem if fluid is too thick to flow through the coolers?

Thank you for the info :bow:

 

[Dysfunctional]

Sorry, but it is best to leave the bypass off! This is the cause of most tranning overheating problems. The bypass was used to heat the fluid on units without rad cooling and cheaper to leave in instead of removing. If you had that much converter clutch in the cooler you will have failure soon.

Just to help,if you plan on installing the other parts of the transgo kit you need a better snapring then the one furnished in the kit.This the second design and will still pop out! If you use manuel 1 or 2 on decell then install the tugger. If you do not this part of the kit does nothing for you.

Transman

I've noticed my trans warms up the same whether the bypass tube is on or off.

Are you saying that even a little TC clutch material will lead to failure soon, or having enough TC clutch material to create a blockage will lead to failure soon? It wasn't *that* much... but it wasn't 3 little pieces either

Where can I get a better snapring than what comes in the tugger kit? I have and need to use manual 1 or 2 for compression braking. I thought I'm ok doing that, because I did do all the VB mods with the tugger kit. I just never pulled the trans and did the front pump part of the kit.

thanks!

 

[LarryM]

I'll make a couple of comments to further the discussion along. Just remember that I'm a non tranny expert, but who has read tons of tranny posts since 2001 so take these with whatever amount of salt you want and the last time I can remember staying at a Holiday Inn Express was over 10 years ago :redspotdance:

My understanding of this bypass based on the following information from someone I believe should know something in fact a lot about the 4R100 tranny ...

The bypass is a pressure relief valve. When it's very cold the fluid in the cooler gets vaery hard to move. Pressure in the cooler line goes up and nothing flows. Since the return from the cooler is used to lube the rear half of the transmission, no cooler flow causes big problems.
If the pressure gets high enough the bypass opens and sends fluid to the rear lube

The internal bypass came out with the TorqShift. The 4R100 is external.
Yes, the bypass was to fix a problem. The fluid in the coolers would get to thick to flow in extreme cold weather. This starved the rear half of the transmission for lube. The bypass allows rear lue to always have fluid.

I do agree that a bypass failure can send temps sky high and IMHO is one reason to have a good tranny temp gauge installed, know your baseline and if things go south find out why pronto and fix the issue. But if the temps are cold enough you could starve the rear of the tranny possibly before the temps got out of control. Also if you remove it and and in warmer weather have a blocked cooler as was the situation in this thread it seems the starvation issue could add to the problem, but maybe the temps go sky high before the starvation issue becomes the major factor in a tranny failure. :shrug: I can also see if the bypass gets stuck open then you will also have a heat issue since it will be bypassing the coolers I'm not sure what the extreme temps quoted above mean, but I seem to recall a lot of folks seeing that bypass open even in mildly cold climites when trying to "flush" their trannies when they removed the return line from their trannies to do the flush. From my understanding during the normal "tranny" flush that we do in our driveway we want that bypass closed and during the procedure we aren't lubing the rear of the tranny so some lack of lubrication over time doesn't seem to be an issue the question is how long is too long and that I have no idea.

FWIW: My stock tranny has both the factory OTA and OTW coolers and the bypass and personally I wouldn't just remove it. :shrug: Of course I also have a spare bypass since a new one was put on when my BTS was built and I got the old one from the original tranny that was still working.

Larry

 

[bigblockhorse]

"Sorry, but it is best to leave the bypass off! This is the cause of most tranning overheating problems. The bypass was used to heat the fluid on units without rad cooling and cheaper to leave in instead of removing. If you had that much converter clutch in the cooler you will have failure soon"


If your tranny is smoked from the use of the bypass then you have other issues.

This is really not a bypass, but a check valve.

I know of a few tranny's the bypass saved from destruction.

Leave the thing on there and fix the real concern.

 

[Transman]

This is for all of you to understand how the trans works. Ford had installed the bypass before the superduty. Yes It will open if the cooler becomesplugged.But if your cooler is plugged then the trans has already failed! Ford used the bypass on the superduty to warm the fluid up on the early years with no rad coolers. I have seen a lot of posts about not using rad cooling. You must use engine temp to bring trans fluid to operating temp. The more even the trans fluid stays the longer the life of the trans.

Transman

 

[bigblockhorse]

So the bottom of the radiator will get up to temp before the trans fluid does? I find that interesting. You'd think they would have stuck the cooler in the top.

I find stuff all day that I have to wonder what the hell they were thinking :badidea:

Not starting a war over a damn bypass, they just seem to work fine in hot ass Oklahoma with the coolers set up properly.

 

[bigrpowr]

where transman lives it's average of 110* everyday.

 

[Dysfunctional]

topped out at 118* here on July 5th

 

[Short Bus]

topped out at 118* here on July 5th

Damn and i thought it was hot here lol

 

[Dysfunctional]

So I towed my rock crawler home yesterday (was storing it at my parents) and it's a nasty pull back to my house. Temps went up again and today I hit 210* without a load. Blew the OTW cooler out again and got this... can't really see it all, but I had atleast that much saturday. Oh boy, time to spend money oke:

 

[Transman]

So the bottom of the radiator will get up to temp before the trans fluid does? I find that interesting. You'd think they would have stuck the cooler in the top.

I find stuff all day that I have to wonder what the hell they were thinking :badidea:

Not starting a war over a damn bypass, they just seem to work fine in hot ass Oklahoma with the coolers set up properly.

All manufactures have ran the trans cooler lines through the cool side first since 1956. I find it hard to believe that they are all stupid! Well except when
Ford used the 6.0 to replace the 7.3.

It is not hot in Oklahoma,try 126 and 80% humidity.

Transman

 

[bigblockhorse]

"Ford used the 6.0 to replace the 7.3."


yah that was a big mistake,

if it were that hot here I'd move lol.

 

[Racer X]

From my understanding during the normal "tranny" flush that we do in our driveway we want that bypass closed and during the procedure we aren't lubing the rear of the tranny so some lack of lubrication over time doesn't seem to be an issue the question is how long is too long and that I have no idea.


Larry

No motion of parts such as the driveshaft when your in park in the driveway. Parts not moving won't need lube. Larry, think about a manual clutch. It disconnects the engine from the transmisson. Engines running must have lube on moving parts. Auto Transmissions are differant than engines. The converter is driving the pump for the flush/change your doing. The motion is stopped when you move the lever to P. I don't think you will need to worry as the rear isn't moving for your flush.

It's 1 am and humidity here is 90% or more at 88 degrees. No relief even in the middle of night or early am. Upper 90's and this humidity are a bear. Going outside is like opening the oven door. It's hurricane air without the wind.
:fordoval:
:fordoval:
:fordoval:

 

[444-4D]

This is for all of you to understand how the trans works. Ford had installed the bypass before the superduty. Yes It will open if the cooler becomesplugged.But if your cooler is plugged then the trans has already failed! Ford used the bypass on the superduty to warm the fluid up on the early years with no rad coolers. I have seen a lot of posts about not using rad cooling. You must use engine temp to bring trans fluid to operating temp. The more even the trans fluid stays the longer the life of the trans.

Transman

GEEZ

The bypass is not there to warm the fluid. It is there to provide lubricant to the rear of the transmission in case there is a flow restriction thru the coolers, for whatever reason.

The radiator cooler is not there to bring the fluid to operating temp. It is there to cool the fluid.

 

[bigblockhorse]

can I get an Amen!!!