towing long distance ( locking converter )

mattfu · Post by **mattfu** » Mon Sep 04, 2006 3:30 pm

need some advice guys , i have alot of towing coming up in a few days and dont have time to put in a tranny cooler , or any other towing aid parts. i will be renting a car tow dolly, then towing my 97 sonoma xc about 700 km (400mi) with my 02 sonoma cc . i will then drop off the truck and hook up to a 1600lb tent trailer for a further 800kms (650mi). i know the tent trailer wont be a problem ,and the crew can haul the extended cab no problem , but maybe some advice, i think i read somewhere to tow in 3rd under heavy load? if this is true can i expect normal speed, rpm's, and such? any advice is appreciated guys, thanks

[b]edited title-HJ[/b]

F9K9 · Post by **F9K9** » Mon Sep 04, 2006 4:05 pm

mattfu wrote:need some advice guys , i have alot of towing coming up in a few days and dont have time to put in a tranny cooler , or any other towing aid parts. i will be renting a car tow dolly, then towing my 97 sonoma xc about 700 km (400mi) with my 02 sonoma cc . i will then drop off the truck and hook up to a 1600lb tent trailer for a further 800kms (650mi). i know the tent trailer wont be a problem ,and the crew can haul the extended cab no problem , but maybe some advice, i think i read somewhere to tow in 3rd under heavy load? if this is true can i expect normal speed, rpm's, and such? any advice is appreciated guys, thanks

You do need to tow in third. You will lose your overdrive and you will have higher rpms towing in third versus overdrive. Mileage will suffer, as well. Watch your brakes. They will heat up quick with repeated stops in traffric.l

killian96ss · Post by **killian96ss** » Mon Sep 04, 2006 4:11 pm

I don't tow very often, but I do know that you should always tow in 3rd (3) gear and not 4th (D) especially if towing a heavy load. You could probably tow in 4th if you could keep the torque converter unlocked with a manual override switch.

The reason you don't want to tow in 4th is because you can damage the TCC or 4th gear lock up solenoid with repeated locking and unlocking of the torque converter. I believe the owners manual even says to use 3rd for towing.

Steve

2kwik4u · Post by **2kwik4u** » Tue Sep 05, 2006 3:03 am

Yea, basically what those guys said.

I don't think the SOlenoid or the clutch is the problem, I think it's purely a function of heat.

Locking/unlocking the convertor creates some heat, and heat kills the tranny. I towed my Xtreme on a car trailer last week, and it did fine. used 3rd for the duration of that trip, however I towed the trailer itself without the truck in D, not 3rd. Just keep an eye out for the convertor locking/unlocking, and if it kicks down ONCE going up a hill, no biggie, but if it gains speed, locks, and then loses speed and unlocks again.....you need to go ahead, and pull it down to 3rd.

Also be aware, the convertor still locks in 3rd, however it unlocks alot sooner in 3rd than 4th.

Just keep an eye on your temp gauge and you'll be fine. Try to keep it under the 210 mark, and you shouldn't have any worries.

F9K9 · Post by **F9K9** » Tue Sep 05, 2006 7:06 am

killian96ss wrote:................................I believe the owners manual even says to use 3rd for towing.

Steve

I just checked the online owners 2002 manual and unfortunately it recommends towing in "D" unless you have frequent downshifting. I guess they want to see that Mr. Goodwrench has job security.

2kwik4u · Post by **2kwik4u** » Tue Sep 05, 2006 8:26 am

The sad thing is that most tranny overheating failures will require service once the truck has missed it's 36k miles warranty end.

Dang dealerships.

WVHogRider · Post by **WVHogRider** » Tue Sep 05, 2006 10:22 am

I got the 6yr/100K bumper to bumper extended warranty for free.

My buddy was the salesperson at the time....Now he is the finance manager.....

Actaully, Thanks for reminding me to schedule an appointment...Need the window switch replaced (Window only works when it wants to) and the same one wiper speed problem that everyone else has. Might as well have them replace it the parts now before my warranty is up.

killian96ss · Post by **killian96ss** » Tue Sep 05, 2006 12:04 pm

f9k9 wrote:
killian96ss wrote:................................I believe the owners manual even says to use 3rd for towing.

Steve
I just checked the online owners 2002 manual and unfortunately it recommends towing in "D" unless you have frequent downshifting. I guess they want to see that Mr. Goodwrench has job security.

Interesting!

Here is an exact quote from my original 2001 owners manual regarding towing a trailer. "If you have an automatic transmission you can use THIRD (3), (or, as you need to, a lower gear) when towing a trailer. Operating your vehicle in THIRD (3) when towing a trailer will minimize heat buildup and extend the life of your transmission".

Steve

F9K9 · Post by **F9K9** » Tue Sep 05, 2006 12:09 pm

Top right paragraph on page 270! Does GM hate me that bad after I raised holy he_l over the trim measurements?

Dial-up warning! PDF boobytrap linked above! -HJ

killian96ss · Post by **killian96ss** » Tue Sep 05, 2006 12:15 pm

2kwik4u wrote:Also be aware, the convertor still locks in 3rd, however it unlocks alot sooner in 3rd than 4th.

This is the first time I have ever heard this.

How does the TC lock up in 3rd without the use of the TC lock up solenoid which is only activated in 4th gear.

I'm certainly not saying your wrong, but this is the first time in 15 years I have ever heard someone say that a 4L60E or 700R4 can lock the TC in 3rd gear.

If you are certain that this can and does happen in 3rd gear could you post some info explaining it.

I really want to start some sh%# on some other forums.

Steve

F9K9 · Post by **F9K9** » Tue Sep 05, 2006 12:17 pm

killian96ss wrote:....................................... I really want to start some sh%# on some other forums.

Steve

killian96ss · Post by **killian96ss** » Tue Sep 05, 2006 12:22 pm

f9k9 wrote:Top right paragraph on page 270! Does GM hate me that bad after I raised holy he_l over the trim measurements?

Reed, I never said I didn't believe you!

Apparently the 2002's got a better transmission that doesn't ever have heat build up

, or like you said they want to make sure Mr. Goodwrench keeps his job security.

Steve

F9K9 · Post by **F9K9** » Tue Sep 05, 2006 12:28 pm

killian96ss wrote:... I never said I didn't believe you!

I know you well enough by now to realize that you weren't questioning me

I just find it strange that GM slips little changes in while not announcing tranny changes. I think that they were just pulling a CYA when they modified the manual.

F9K9 · Post by **F9K9** » Tue Sep 05, 2006 12:44 pm

Something just occurred to me in an ironic sort of way. I bet that if the automotive "powers to be" in 1990 would have imagined that automotive enthusiasts would be comparing manual changes made in forums 16 years ("tears" before I edited it hmmmmmmm) later that they would have started building a better product and worried a little less about short term monetary gains.

killian96ss · Post by **killian96ss** » Tue Sep 05, 2006 1:15 pm

f9k9 wrote:I just find it strange that GM slips little changes in while not announcing tranny changes. I think that they were just pulling a CYA when they modified the manual.

I was kidding about the tranny change from 01 to 02 and it seems like GM now wants us to tow in 4th so they can sell more replacement transmissions later down the road.

They have to make money anyway they can to keep from going under right?

Steve

mattfu · Post by **mattfu** » Tue Sep 05, 2006 2:11 pm

thanks guys , i will tow in 3rd for the most part. those of you with tranny coolers notice a big difference? or just a part to keep the tranny safer?

F9K9 · Post by **F9K9** » Tue Sep 05, 2006 2:19 pm

It was a precaution for me. I only tow a light weight trailer a very short distance in the spring of the year with mulch or lava rock.

Snoman002 · Post by **Snoman002** » Tue Sep 05, 2006 2:49 pm

killian96ss wrote:
2kwik4u wrote:Also be aware, the convertor still locks in 3rd, however it unlocks alot sooner in 3rd than 4th.
This is the first time I have ever heard this. How does the TC lock up in 3rd without the use of the TC lock up solenoid which is only activated in 4th gear. I'm certainly not saying your wrong, but this is the first time in 15 years I have ever heard someone say that a 4L60E or 700R4 can lock the TC in 3rd gear. If you are certain that this can and does happen in 3rd gear could you post some info explaining it. I really want to start some sh%# on some other forums.

Steve

After 97 I think the lockup can accour as early as 25 MPH and in second gear, this is partial lockup though, full lockup won't accour untill 45+MPH. In fact this is the main part of the problem that the 98/99's had with the P1870. It is possible the CC's use a different lockup strategy, but I do believe that any S-10 after 98 uses the ECCC lockup strategy.

The biggest benifit with towing in third is the 1:1 ratio, there is a direct connection between the engine and the driveshaft (or t-case). When towing in fourth there is a gearset in use to give the overdrive. I'm sure by now GM has built the gearset tough enough to tow with, well, maybe they did

.

Also, you also WANT the torque converter locked while towing. With the converter UN-locked a TON of heat is generated, locking the convterter prevents this heat buildup. Heck, most of the tranny heat comes from the normal converter slippage.

What this means is that if you tow in fourth (which is fine) and do alot of mild hills don't try and keep the speed constant, try and keep the converter from unlocking, which may result in your speed slowing when going up hill (but boy the downhill can be fun).

Edit:

In the quest for better gas mileage GM has changed the lock up strategy of the torque converter over the years. The original 700 and 93-94 4l60e used an on/off type lockup. Meaning it was off or fully locked on.
In 95 they went to a PWM (pulse width modulated) lockup, which controls the aggressiveness of the apply and release of the torque converter clutch and allows a bit of slippage for a smoother feel.
In 98 GM went to a different strategy called “Ec3”or electronically controlled capacity clutch.
This strategy has made a big difference in fuel economy by starting the apply of the Tcc at much lower speeds and continually slips until it reaches highway speeds. It begins to apply in 2nd gear and slips up to 250 rpms depending on speed and engine output. In order for this strategy to work a new converter clutch lining had to be developed to withstand the slippage and heat generated. What GM came up with is a woven carbon fiber material that is very porous that allows fluid to flow though it for better heat transfer. This stuff is practically indestructible. One of the problems shops face is getting a replacement converter when doing a rebuild. GM holds a patent on this material. The aftermarket converter companies have been trying to find a suitable replacement material that will hold up. Several companies are very close to releasing their own material. Until then we have only two choices, get a rebuilt converter with a good “used” woven clutch or buy the converter from the local GM dealer. I personally prefer to go new. I just don’t trust a used lining although this stuff is extremely durable.
The 4l80E uses the PWM type strategy and uses a graphite/ Kevlar composition lining for the Tcc.
The 4l60E PWM units use this material also.

From Here: Avalance Fan Club

There was alot of info on the Sonnex site, unfortunatly I cannot find it anymore to verify.

killian96ss · Post by **killian96ss** » Tue Sep 05, 2006 6:21 pm

Thanks for the info Snoman002.

I thought the info on the topic "Inside The 4l60E/4l85E Q&A's" was very interesting.

Now I just have to try and make sense of all of it.

Steve

2kwik4u · Post by **2kwik4u** » Tue Sep 05, 2006 6:55 pm

killian96ss wrote:
2kwik4u wrote:Also be aware, the convertor still locks in 3rd, however it unlocks alot sooner in 3rd than 4th.
This is the first time I have ever heard this. How does the TC lock up in 3rd without the use of the TC lock up solenoid which is only activated in 4th gear. I'm certainly not saying your wrong, but this is the first time in 15 years I have ever heard someone say that a 4L60E or 700R4 can lock the TC in 3rd gear. If you are certain that this can and does happen in 3rd gear could you post some info explaining it. I really want to start some sh%# on some other forums.

Steve

I'll get the stock TCC lockup tables posted here shortly....I'll start a new thread so as not to muddy this one.....

Also the 700R4 in the Sy/Ty tranny will lock once shifted to second, if you ground a pin on the ALDL connector. Been proven many many times.

BRB, with a new thread, and some screen shots

......

BTW I think it actually locks in second as well, but I'm not 100% sure.

1337vending · Post by **1337vending** » Tue Sep 05, 2006 9:46 pm

BTW I think it actually locks in second as well, but I'm not 100% sure.

Not with the stock programming (in '03), but I have mine set to start locking around 3500 rpm in 2nd....seems to keep it in the powerband longer.

2kwik4u · Post by **2kwik4u** » Wed Sep 06, 2006 3:32 am

Confirmed....Stock programming has it unlocked through all of second. However it will lock in 3rd with stock programming.

Pauleo · Post by **Pauleo** » Wed Sep 06, 2006 5:46 am

When I towed with my S-10, I always used 3rd gear. But the brakes are what I always worried about. They will heat up VERY quick! I could smell mine burning on several occasions when some idiot would pull out in front of me or when I was the idiot and didn't allow plenty of stopping distance.

All the info on the locking & unlocking of the TC is really good stuff! But again, my greatest concern was the brakes.

EDIT:

Now that I read the original post over again, I see that we are talking about a very long distance hike! I guess I WOULD be paying more attention to the tranny and stuff with that many miles ahead of me!!! My towing experiences have been limited to jaunts of 20 miles or less.

crew cab sonoma · Post by **crew cab sonoma** » Wed Sep 06, 2006 5:51 am

here is another link that explains GM`s current "ECCC" and older "PWM" variable lockup stratagies. its a rather long read, but quite informative...

many owners often mistake ECCC as a worn, or failing clutch, when the slippage is actually by design...

http://www.sonnax.com/bulletins/tech/TS-BW-699.pdf

mattfu · Post by **mattfu** » Wed Sep 06, 2006 9:47 pm

ok last towing question i promise as i am leaving in a few hours, our manual indicates to never tow with wheels on the ground, this is obviously not always practical, i have a tow dolly (front tires on) my question is will i really do any damage to the towed vehicles tranny with the rear wheels turning as i tow? i realize the tranny wont have the complete lubrication as it would running , but am i really going to hurt anything? is it really worth the trouble to pull one end of the driveshaft off ? or should i rely on tranny fluid splashing around enough ?

F9K9 · Post by **F9K9** » Thu Sep 07, 2006 1:57 am

It will hurt an auto tranny. If you are towing a 4x4 with auto a dolly will not work unless you pull the drive shaft and have the front on a dolly. I have heard of people towing long distances with the towed vehicle in neutral and "RUNNING" for hundreds of miles w/o problems.

mattfu · Post by **mattfu** » Thu Sep 07, 2006 2:26 am

no the towed truck is 2wd 5spd standard , so ill throw it in neutral and hope for the best

F9K9 · Post by **F9K9** » Thu Sep 07, 2006 2:32 am

mattfu wrote:no the towed truck is 2wd 5spd standard , so ill throw it in neutral and hope for the best

Should be fine. I'd pull the shaft as a precaution depending on distance.

S-10CREWCAB.NET

towing long distance ( locking converter )

towing long distance ( locking converter )

Re: towing long distance