Community Forums

hzjcm8 · 06-29-2011, 02:21 PM

Quote:

Originally Posted by TNStreamer

I have a 2009 Winnebago with the W22 Workhorse chassis and Allison 1000MH transmission with 3000 miles. Last week on a return trip on I26 from NC to TN there was a short period where the steep grade caused the transmission to shift to 2nd. The water temp went to 222 degrees and the RPMs were around 4000. The transmission apparently vented because my toad was lightly coated with trans fluid. I did a cold check of trans fluid level the next day and it showed to be about a half inch below the cold level mark. Is it normal for venting to occur in these conditions? The transmission had not previously leaked any fluid. Also, should I change the spin-on filter now rather than wait for the 5000 mile interval since the transmission was probably built in 2008?

TNStreamer,

It is never a good thing for transmission fluid to be expelled from the vent tube. In fact in can be dangerous. If the level is too high (check it on a flat surface in the operating temperature band), it could spit if it's foaming from getting into the rotating clutches at the front of the tranny. I'd also do a fluid analysis to make sure the viscosity is not too low or if it's contaminated in some way that has thinned it out which would exacerbate the problem.

TNStreamer · 06-29-2011, 05:27 PM

In researching this problem, I read that some Allison transmissions had dipstick tubes without a small vent hole near the top and this could cause fluid to be expelled from the vent on the transmission. My tube has no small vent hole at the dipstick insertion point. Is there supposed to be one on a 1000-MH?

hzjcm8 · 06-30-2011, 04:59 AM

Quote:

Originally Posted by TNStreamer

In researching this problem, I read that some Allison transmissions had dipstick tubes without a small vent hole near the top and this could cause fluid to be expelled from the vent on the transmission. My tube has no small vent hole at the dipstick insertion point. Is there supposed to be one on a 1000-MH?

TNStreamer,

I'll check it out and get back to you.

hzjcm8 · 07-03-2011, 05:47 PM

Quote:

Originally Posted by hzjcm8

TNStreamer,

I'll check it out and get back to you.

Check the dipstick itself to see if there's a small hole or channel in the flange where the top of the dipstick installs into the top of the dipstick (fill) tube.

TNStreamer · 07-04-2011, 04:03 PM

Quote:

Originally Posted by hzjcm8

Check the dipstick itself to see if there's a small hole or channel in the flange where the top of the dipstick installs into the top of the dipstick (fill) tube.

I removed the dipstick and could not see any hole in the plastic cap; however, I removed the small roll pin holding the plastic cap to the steel dipstick and discovered the dipstick tube is vented through a hole in the center of the rubber insert where the steel dipstick passes through, and the plastic top covers it but does not seal it. Thanks for helping clear that up.

I believe the amount of fluid expelled was small since there was very little on the bottom of the chassis. It definitely came from the transmission vent, and I feel it was probably caused by high rpm's, high ambient temperatures and multiple long 6 percent grades. I was using the grade brake feature on the transmission on the descent. Also, the transmission warning light never indicated a problem.

Mr_D · 07-07-2011, 08:16 PM

Spartan chassis, ISC 350, Allison 3000 MH. Where would my trans temp sensor be located and what would be the max temp I should ever see?

AFChap · 07-07-2011, 08:59 PM

Same set-up except w/o the Banksan my normal tranny temp is around 180. I have seen around 200 on a few rare occasions on extended steep climbs in summer weather.

hzjcm8 · 07-08-2011, 05:35 AM

Quote:

Originally Posted by Mr_D

Spartan chassis, ISC 350, Allison 3000 MH. Where would my trans temp sensor be located and what would be the max temp I should ever see?

Mr_D,

The temperature sensor is part of the wiring harness on the valve body in the sump. You could run up to 250F and still be OK. However, that's not normal. I'd say you should normally run between 180F and 220F depending on amount of shifting, amount you're in converter mode and cooling system capacity. City buses run for many many miles at these temperatures so your RV should be fine.

Happy Motoring !!!

PS: Always use oil analysis to get the most from your engine and transmission fluids. You can save a ton of money over the life of the RV and do it "safely".

USAFretarded · 07-08-2011, 07:45 AM

Do you know if Citgo quadrasyn is approved for use in allison transmissions. Have access to this fluid and it's time to service 3000MH. Thanks.

DriVer · 07-08-2011, 12:22 PM

Quote:

Originally Posted by USAFretarded

Do you know if Citgo quadrasyn is approved for use in allison transmissions. Have access to this fluid and it's time to service 3000MH.

Respectfully, I would dump anything with a Citgo label into a recycling drum.

hzjcm8 · 07-08-2011, 01:17 PM

Quote:

Originally Posted by USAFretarded

Do you know if Citgo quadrasyn is approved for use in allison transmissions. Have access to this fluid and it's time to service 3000MH. Thanks.

Here's the official list. If it ain't on there, don't use it !!!!

Allison Transmission

Mr_D · 07-08-2011, 01:49 PM

Quote:

Originally Posted by hzjcm8

Mr_D,

The temperature sensor is part of the wiring harness on the valve body in the sump. You could run up to 250F and still be OK. However, that's not normal. I'd say you should normally run between 180F and 220F depending on amount of shifting, amount you're in converter mode and cooling system capacity. City buses run for many many miles at these temperatures so your RV should be fine.

Happy Motoring !!!

PS: Always use oil analysis to get the most from your engine and transmission fluids. You can save a ton of money over the life of the RV and do it "safely".

OK, my temp gauge and my VMSpc usually show about 175°-177° on the flats and maybe 190° at the most.
Yes, I do have TranSynd, that caused about a 20° drop in temps. I have a hard time using the level sensor now unless I preload the trans against the brakes to heat it up enough.

92hummer · 07-09-2011, 10:53 AM

Am I to understand from your previous post regarding adding trans fluid that I can add TranSynd to whatever is in the trans now even if it is Dexron? or are you talking about replacing. Thanks I confuse easily.

hzjcm8 · 07-10-2011, 01:39 PM

Quote:

Originally Posted by 92hummer

Am I to understand from your previous post regarding adding trans fluid that I can add TranSynd to whatever is in the trans now even if it is Dexron? or are you talking about replacing. Thanks I confuse easily.

92hummer,

I'm not sure which post you're referring to. But, here's the deal. Yes, you can add TranSynd to any DEXRON-III or DEXRON-VI but you won't get the full benefit of TranSYnd (or one of the other licensed TES-295 fluids) because it will be diluted by the other fluid already in the transmission. It won't hurt anything and it won't damage the transmission to mix TranSynd (or another TES-295 licensed fluid) with DEXRON-III or DEXRON-VI.

If you want the most from TranSynd, and you currently don't have it in the transmission, then you'd want to drain the old fluid, change the filter, install TranSynd, drive it around for 1/2 hour or so, drain it again and then reinstall TranSynd. Then, you'll have the full benefit and probably be "fill for life". You'll just want to do a yearly fluid analysis to make sure it doesn't get contaminated in any way.

Make sense?