GREATEST cause of auto tranny failure?

[35Remmy]

OK...so Glacier has mentioned that MOST of the bands in the transmissions he has disassembled have had MOST of their friction materials left.

I always thought that failure of the bands was the #1 reason why trannies failed.

If Glacier's observation is true, what, then, is the single greatest cause of automatic transmission failure, besides heat?

Or me getting pissed off at my tranny and beating it even more?

 

[GPNyce]

i would say this is a hard question to answer, as no two transmissions have been 'driven' the same. as for me, my torque converter blew up and sent shards of metal throughout the rest of the tranny.

 

[BrooklynBay]

Heat from friction, filings, band material, clutch plate material, seal material, gasket material, clogged valve bodies, leaking bores, broken bands, dried seals, and servos, etc contribute to transmission failure. On newer transmissions, it would be failed solenoids, and wiring harnesses. Bad sensor input, or a bad PCM could cause the transmission to act like it failed.

 

[96eb96]

OK...so Glacier has mentioned that MOST of the bands in the transmissions he has disassembled have had MOST of their friction materials left.

I always thought that failure of the bands was the #1 reason why trannies failed.

If Glacier's observation is true, what, then, is the single greatest cause of automatic transmission failure, besides heat?

Or me getting pissed off at my tranny and beating it even more?

Barring any manufacturing or electronic issues, I was told by a very reputable trans shop owner that neglecting fluid/filter changes can be implicated in the majority of his rebuilds. The next thing is flushing neglected trans wth chemicals, he even showed me gummed up Valve bodies from that. He even went on to say that if everyone changed their fluid and filter on time, he would probably be out of business. Since fluid does so many functions, and will degrade over time, there is a big clue there.

 

[protomind]

I would guess that heat is the big one to worry about in most cases, especially older cars. If you neglect to change your fluid, it breaks down and looses its ability to lubricate properly, which causes friction, which creates extra heat.

 

[4x4junkie]

Running around with oversized tires and stock (or too-tall) gears is a huge source of heat generation in an auto trans, this can kill them real quick as well (even stock tires with crappy 3.27 gears isn't all that great on them either)

 

[Glacier991]

If I had to try and answer in a way that covered a majority of failures.... regardless of how it came about, I'd say in one word - HEAT.

That will not explain 100% but certainly a majority.

 

[glfredrick]

I agree with Glacier -- except for one caveat.

The greatest cause of Ford Explorer and Ranger transmission failures is a SERIOUS DESIGN FLAW by Ford. The transmissions are WAY undersized and there is no way that they will hold up to the sort of loads that we put on them. The undersized nature causes them to run hot, and after that the trouble is inevtable.

I've had two Explorers and a Ranger -- I've gone through 7 transmissions (A4LD and 5R55E). I have the last 4 in the scrap pile right now. Worth more to me as aluminum.

Kudos to Ford for fortifying the old C3 as much as they have -- but they should have started with the C4 as a base -- it could handle the loads SO much better than a transmission designed to run a 4 cyl. Pinto!

My Ranger SAS build will run a C4/5 modded with a reverse valve body and hold in all three forward gears.

 

[35Remmy]

GL, my '88 Ranger STX went about 200,000 before the A4LD took a crap...now, for about 100 THOUSAND miles, that transmission SLAMMED into 1st gear, SLIPPED in other gears, SHUDDERED whenever it felt like it, etc. In it's last couple of months, it would SLAM into reverse, heheh.

It acted like it was going KAPUT for THAT long.

The master tech at the Ford dealer I worked at said that he couldn't BELIEVE that I wasn't breaking anything with the transmission slamming like that.

I LOVE that transmission now, after the rebuild...shop did a LOT of work/upgrades to it.

*NOW I'm dealing with my 5R55E...how did or what happened when your 5R55E's went out?*

I think I'm going to design a HUGE transmission cooler and fab it into place somewhere...like the size of the radiator, adding about 8 quarts of fluid.

Will this work or am I out of my mind? I CAN design it.

 

[Glacier991]

Let's remember what the Ford Explorer did. It really started the SUV revolution. I think FORD engineers saw it as a soccer Mom "station wagon" kinda vehicle.... and for that the A4LD seemed well suited. In fact my 92 has 233,000 miles on tyhe original engine and tranny... and I admit it... I'm a "Soccer Mom" kinda user... I drive it up from sea level to 7000 feet in the Sierra regularly, but always on road. In fact I bet I have under 10 miles off road in it, but LOTS of 4WD!

But what FORD never figured was that it might be seen as a real off-road vehicle. On that point my good friend GL is EXACTLY right. The trans is undersized, undercooled and poorly designed for that use. Then add the younger crowd these days who either have one foot on the floor on the accelerator or brake (and older Explorers were cool for them to own) and the same thing happens.

It has been interesting to watch the evolution from the C-3.

As I have said it in other threads - designing and tooling a new tranny from the ground up these days is nearly a billion dollar task! No wonder they try and adapt older models. Witness is the fact that the Pinto C-3 is now a prototype for the Jag 5R55S!

From a science standpoint, FORD did too much at once when they designed he 4R44/55 and 5R55. They changed so many things it as hard to tell what caused what! They took the A4LD and realistically FIXED all the internal problems by putting bearings EVERYWHERE! ....BUT!!! then they added a new and as yet unproven totally electronic shifting system. THAT was a problem.

I still think a Frankentranny and some well fanned coolers ourboard will allow some pretty harsh off road use.... without the A4LD world of puny problems. Those bearings make it pretty strong mechanically believe it or not...feed it clean cool fluid and prepare to be amazed.

Nitrous folks need not apply.

My 2 cents on this issue.

 

[MountaineerGreen]

I am still amazed that they continue to use the same problem prone transmission in hundreds of thousands of vehicles. It seems the "back eye" of failing transmissions would detour them from wanting to do so. I passed up a nice sport trac for fear of transmission issues. I know the development cost of a ground up transmission is substantial, but why not adapt the robust 4R70W and use it?

 

[Glacier991]

No argument there. I think the 4r70W is a great transmission... but the genesis AOD was a POS. So same/same.

 

[storlied]

Yeah, the 4R70W is great.. and can take plenty of abuse.

 

[Andy96XLT]

how is the 4r55e? Im going off roading tomorrow for the first time and I have 150K on the clock and starting to get worried after reading all these things lol

 

[glfredrick]

*NOW I'm dealing with my 5R55E...how did or what happened when your 5R55E's went out?*

I think I'm going to design a HUGE transmission cooler and fab it into place somewhere...like the size of the radiator, adding about 8 quarts of fluid.

Will this work or am I out of my mind? I CAN design it.

I've seen 3 roasted forward sun gears, 1 set of burned up clutch plates, two valve body gaskets blown out, 2 solenoids that failed due to crud, a broken band, 4 front seal leaks that were bad enough to puke on the road, 3 blown accumulator seals, one blown clutch drum (all the springs were tossed around like salad!). Some of the transmissions obviously had more than one problem.

I'm not even hard on my transmissions... No power shifts, very occaisional towing, change oil and filters regularly, off-road use, sure, but I'm not generally a throttle jocky, and they still failed. On my 92, I ran a motor-home-sized cooler -- it barely fit in the grill area (had to run it an an angle to make it fit!). I did find that an external filter helped a LOT, especially on the 5R55E. Tap it into the cooler line. There's a great thread here on the forum about that somewhere. I now do that as a matter of course on all my autos.

Oh, I moved to a Chevy Trailblazer after all the issues with the Explorers. I know that "Chevy" is a dirty word on this forum, but I needed someting that could tow. It has an electronic version of the 700R4 that Explorer dudes are now swapping in... I've towed about 8000# behind it with no problems. In current tune, it puts out about 325 HP, and runs nicely down the road with this load.

Mods to the TB include, K&N Drop in, PCM for Less computer re-flash, 265/70/16 tires, Sonnax 1/2 valve and pinnless accumulator in the tranny, additional oil filter and cooler for tranny, Amsoil all around. 23 MPG on the highway.

 

[Glacier991]

The 700R4 is Chevy's 4R70W. It is also a great tranny. Also derived from crappier early versions. I MAY do a 700R4 Diary on another site.

I will look for a pic I have of a Ford towing setup..... wkth a Bronco sitting in a Boat being towed along the Alcan highway, by a Ford truck.

 

[35Remmy]

UCORA u DIDN'T!!!

I used to work in parts, and Chevy Trailblazer was like a CURSE word!!! We sold SOOO many parts for those trucks. I think the ONLY vehicles we sold MORE parts for were Blazers.

NO ONE I worked with would purchase a Blazer because of the sheer volume of parts we sold for them.

Would you like to know what brand of truck out of the Big 3 we sold the LEAST number of parts annually INCLUDING all 50 states?

FORD

I'm certainly NOT saying they don't have problems...but now I understand why, say, the F150 has been the best selling vehicle in the U.S. for 31 years and TEXAS sells more FORDS than any other state in the nation.

FORD makes a GREAT truck.

 

[Glacier991]

All I said was the current 700R4 is in my humble opinion a great tranny, as is (again IMHO) the 4R70W. Both had growing pains and bad birthing.

 

[35Remmy]

GLACIER and UCORA, what do you two think about my "enlarged" tranny cooler idea? 8 quarts extra would be SWEET!!!

It would be pretty easy to do, too.

GLACIER, what the heck is your name, if I may ask?

Mine is Anthony...I HATE calling people by their screen names...like, "hey, 35Remmy"....weird.

35 Remmy is short for .35 Remington, my favorite deer rifle, my Marlin 336 in .35 Remington.

 

[BrooklynBay]

His name is Chris.