HT740 slipping

lostagain · August 01, 2020, 08:19:30 AM

A couple of years ago, I installed a filter on the line between the converter and the shell cooler that is on the side of the engine. Would it be better in the return line? I thought being on the out line, it would take a bit of heat off before it got to the cooler. Of course, I still have the regular filter on the other side too.

Interestingly, when I limped it home with it slipping, the trans temp went up to 220F from a normal of 180, 190F. But the engine temp stayed normal at 190F. It was fairly warm outside. So I guess the engine temp is not as affected by the transmission as I thought.

luvrbus · August 01, 2020, 08:24:50 AM

Quote from: lostagain on August 01, 2020, 08:19:30 AM
A couple of years ago, I installed a filter on the line between the converter and the shell cooler that is on the side of the engine. Would it be better in the return line? I thought being on the out line, it would take a bit of heat off before it got to the cooler. Of course, I still have the regular filter on the other side too.

Interestingly, when I limped it home with it slipping, the trans temp went up to 220F from a normal of 180, 190F. But the engine temp stayed normal at 190F. It was fairly warm outside. So I guess the engine temp is not as affected by the transmission as I thought.

There is lot of hype about how much heat the Allision affects the engine temps the plate cooler does a damn good job

Jim Blackwood · August 01, 2020, 12:09:25 PM

a slipping transmission will make more heat. it's a vicious circle.

Paso One · August 03, 2020, 03:46:29 PM

JC I am glad you are making use of Joe's transmission. It certainly looked good in his shop. Along with its history.
At one time I was thinking of installing a automatic in my 5B I was considering buying that 6V92 he also has in his shop, and the tranny you bought and install them at the same time.
But things changed and I learned to downshift properly LOL.

lvmci · August 03, 2020, 06:02:24 PM

Hi JC, I thought you might like this photo, from BC. A guy named Simmons, on facebook...

lostagain · August 03, 2020, 08:46:21 PM

Tom, I think this photo is in the West Kootenays of BC. Very mountainous with lots of lakes.

I am slowly making progress on my project. The trans is off the engine. I took the flex plate off the crank shaft and removed the rear seal that looked like it was starting to weep a little. Tomorrow I will get a new seal at the DD Allison dealer. Then the rebuilding process begins... I refer to the service manual a lot, and have been on the phone with Clifford almost every day for advice. I am lucky that I can do this at home in my shop. I shudder to think about the hassle of the transmission failing far from home...

dtcerrato · August 04, 2020, 11:38:00 AM

Quote from: lvmci on August 03, 2020, 06:02:24 PM
Hi JC, I thought you might like this photo, from BC. A guy named Simmons, on facebook...

LOVE THAT PHOTO!

lostagain · August 08, 2020, 08:19:29 AM

Over the hump now!

The sleeve and rear seal were almost $300 at the Detroit dealer, gulp... Installed them yesterday, put the flex plate back on. I took the pan off the rebuilt transmission of Joe's. Looks good. Lots of fresh looking ATF left in there I am assuming from Dynoing it after the rebuild. Drained as much off as I could. Will refill with 15W40. Re installed it onto the back of the engine. The motor mounts that hold the tranny to the cradle make it difficult. Then you have to align the bolt holes to the bell housing, then align the flex plate to ring gear bolt holes, etc. Today will reinstall the compressor, PS pump. Made some new gaskets. And the alternator (belt driven). Then there will be another day to finish tidying up the engine bay before I push the engine back in. Then another couple of days to reconnect all the wires and coolant lines, and turbo and exhaust and intake plumbing. Oh and I want to move the EGT probe from after the turbo to upstream of it on the manifold Y. Lots to do...

Utahclaimjumper · August 08, 2020, 08:29:34 AM

Looks like your rocking and rolling right along JC..>>>Dan

Stormcloud · August 08, 2020, 08:29:56 AM

Wow! Parts are plenty ex$pen$ive!
Glad you are getting to the good part, where it all starts coming together. It is a GOOD feeling.
I've never though of using 15W40 in my trans. I have Dexron3 in it right now, and had considered using 30W. Prewarming prior to use may be an issue here in our climate.
Following with interest!!

Mark

lostagain · August 08, 2020, 08:38:39 AM

Look at the Allison literature. 15W40 C4 is one of the approved fluids for the 700 series. I find it shifts smoother, and runs a little cooler maybe. Starting on a cold morning, I preheat the engine. You could idle for a few minutes to warm up the trans before moving.

Stormcloud · August 08, 2020, 08:51:57 AM

I'm about due for a fluid change in the trans. I'll check the Allison recommendations first..I have several pails of 30w, and I think a couple of pails of Dex3 here already.
The Dex3 seems to work well in my MT654, and shifts well.

We won't be seeing you in AZ this winter. Perhaps next year, if things improve.

Mark

luvrbus · August 08, 2020, 09:03:25 AM

Quote from: lostagain on August 08, 2020, 08:19:29 AM
Over the hump now!

The sleeve and rear seal were almost $300 at the Detroit dealer, gulp... Installed them yesterday, put the flex plate back on. I took the pan off the rebuilt transmission of Joe's. Looks good. Lots of fresh looking ATF left in there I am assuming from Dynoing it after the rebuild. Drained as much off as I could. Will refill with 15W40. Re installed it onto the back of the engine. The motor mounts that hold the tranny to the cradle make it difficult. Then you have to align the bolt holes to the bell housing, then align the flex plate to ring gear bolt holes, etc. Today will reinstall the compressor, PS pump. Made some new gaskets. And the alternator (belt driven). Then there will be another day to finish tidying up the engine bay before I push the engine back in. Then another couple of days to reconnect all the wires and coolant lines, and turbo and exhaust and intake plumbing. Oh and I want to move the EGT probe from after the turbo to upstream of it on the manifold Y. Lots to do...

300 I hope that was Canadian,a good one from DD are around $120 to $150 here the after market crap is a lot cheaper around 80 bucks for the set

Dave5Cs · August 08, 2020, 11:43:06 AM

Nice JC, yep me too Mark I use Dex 3 in my MT654.

DoubleEagle · August 09, 2020, 10:24:45 AM

Quote from: lostagain on August 08, 2020, 08:38:39 AM
Look at the Allison literature. 15W40 C4 is one of the approved fluids for the 700 series.

That used to be true, but Allison dropped recommending oil and Dexron fluids with Service Tip #1099 (June 2018). They recommend approved TES 295 fluids (not just Transyd) for all series including HT700. I realize Cliff says HT740's love having oil in them, and it was used for severe service duty for years in vehicles like garbage trucks, but the Allison Engineers have revised their thinking even though the HT740 is considered obsolete.