[Jimdear2]

A thought about a possible problem with an accumulator.

Depending on it's volume, possible overfilling and/or fluid starvation of the transmission.

Another reason to stay with a pump

Jim

[madmike8]

Good thread Miz. Since I'm building a T-bucket, I've been keeping up with your thread. I really like the idea of using a powerglide. I will be starting off with a T5 since I got both my S10 rear axle and T5 for $150. I think the wife will find a powerglide easier to use, so I will be looking to pick one up and modify in the near future.

[mizlplix]

Jim:

The optimum fluid level on a powerglide is 3/4" below the case hole where the dipstick tube plugs in. (it is actually above the pan gasket seam.)

The only critical time for an overfill condition is when Things are turning. Parked is not so critical because nothing is turning to agitate the oil. You just need a tight transmission, like usual.

When using an accumulator, you need to fill the transmission, then fill the accumulator, then set the fluid level in the pan, with the dipstick.

This will duplicate the operating condition while driving and things are "flying" around inside the transmission, normal oil level, accumulator filled.

You stop driving, the accumulator bleeds back keeping the low band engaged. When you start out, the oil level will be over full. But the planetaries will be stopped or very slow. the accumulator will refill very quickly as you go, my theory has it that the accumulator refills so fast that the time the extra oil is present, is of no consequence.

I have actually tested this by overfilling 2qts too much and driving around.

One point not mentioned.....

My dip stick tube hole in the transmission case is threaded 1/2"NPT. A heater hose fitting is screwed in there. I use a piece of 3/4" silicone heater hose there and cut off the dipstick tube to match. It gives a completely fluid tight connection that will not leak there as it eliminates the pesky o-ring.

I feel a 1qt. Accumulator will be sufficient, if the transmission is internally tight.


Anyways, that is another test for another day...

Miz

[dreamer]

Originally Posted by mizlplix

Or just buy a TCI 742011 "Circleglide" from Jegs for $1,001.99 USD. and cut the bell off with a saw and sand it down to the existing flat. Use the pump I show in the thread. (later).

http://www.jegs.com/i/TCI/890/742011...72#moreDetails



OR, Get an old one and follow my instructions. It is easier than it looks and would cost about $400 USD less.

Miz

Both the Jegs and the Kansasev Powerglides are set up for manual shifting. Are you doing the same, or maintaining the "automatic" aspect of the the Powerglide ?

If someone wanted to maintain the "automatic" behaviour of any AT, what is the advantage to doing all the work you've laid out here vs. using the AT as is, including torque converter, and simply setting the motor controller to spin the motor slightly below stall speed ?

[mizlplix]

95% of my driving is city streets.....0-45 mph. I don't want it to shift. But I still wanted high gear for expressway driving if I so chose.

A circle glide has had a steel forward hub installed. A tougher low band. Half of the valve body gutted, some reverse clutches removed for lower friction. The torque converter removed for lower overall weight, lower rotating mass and lower heat. Actually, the torque converter is 90% of the total heat.

An automatic shift transmission would have worked I guess, but this one is a tad lighter.

Ah....the torque converter....yes, you can retain it and idle the motor about 50rpms to keep the low gear band engaged. I just see them as current wasters. Both idling, rotating weight and slippage are not optimal in an EV.

To be fair, a low stall converter can be made to make it better for our use though and the lock up feature of some can be turned on early in first gear for lower slippage.

Miz

[dreamer]

Ah, yes. I had forgotten how heavy a TC can be and the rotating weight and drag on the motor could eat a lot of watts, couldn't it ?

I wonder if the drag would be less on a CVT or even if continuous spin is necessary for a CVT like the one in the Murano. I'll have to research how those work. All I know about them at this point is that reliability was poor for some years.

[DanGT86]

Seems like the CVTs are more for catering to the narrow power band of an ICE. Most electric motors used in conversions seem to be efficient enough over a wide range to make the cost and complication of the CVT not worth it.

Seems to me that the perfect EV trans for most street conversions is one like this powerglide that can keep the amps reasonable at takeoff but keep the rpms reasonable on the highway.

Miz, do you think the lack of engine braking on a non regen conversion would cause any problems in low gear at high road speed? I know drag racers are always arguing about powered vs non powered down shifts with manual valve bodies. The circle track guys don't spend much time in low gear either as far as I know. Seems like the lack of engine resistance could let a drum overspeed or something like that.

[mizlplix]

Dan: (and eveyrone else) We are starting to drift...

In my first page of this thread I said:

The Powerglide whys and wherefores have already been discussed in great length in several other threads. This one is just for the technical side.

I wish this thread to stay focused on purely mechanical issues during the powerglide rebuild. There are a couple of other powerglide threads to post operational questions.

If asked in them,I would be pleased to answer.

(not trying to be an ass), Miz

[mizlplix]

When reassembling the transmission, it needs to be in the verticle position, to make things fit. I have devised a simple stand that does this.

It is made from an old implement disk, a 12" piece of electrical conduit, 10" X 1" x 1/4" flat bar and a 5" piece of 1" X 1" angle.

The internals can be assembled, end play set and then it can be removed from the stand and placed flat on the table for final assembly.

As mentioned previously, a hole must be drilled in the front pump's high pressure port to accept the pre-charge pump output.

"X" marks the spot. (to drill)...Heh...(1/4" NPT for me)

When inspecting your transmission, one place is really very critical.
The front pump bushing contact area, where it rides inside the front planetary hub.

This is a sealing area that holds the high gear apply pressure. This one is too far gone to save....(Crap) It is easy to tell, just place the new bushing over it and it flops around a LOT. NOTE: that small oil hole seen near the copper thrust washer gets drilled out for extra oiling. (More later)

If you place the two gears in mesh, on a flat area and pull the bigger one with the smaller one without unmeshing, they are good to reuse.

Notice how far these get out of contact and barely stay engaged. They are almost out of spec.

A worn bushing contact area, the gear wear and the pump gear cavity side scratches and it all sez I need another pump.....

More tomorrow, (Yes, I am playing sick from work.) Miz

[mizlplix]

Today was "bushing Day".

I started replacing the 5 really important bushings. By that, I mean the ones that assist in holding hydraulic pressure or the thrust areas.

The first was this one in the bottom of the case. It was the hardest to do because of the location.

The old one must come out first.

I Use a AWL/punch that was converted to a small chisel.

You just collapse one side and it pops right out.

And the one inside the forward drum-

It is the key to holding clutch apply pressure in high gear.

And the one inside the front pump-

It keeps up pump pressure and the front drum aligned for the band to grip.(low gear)

Followed by-the one in the tail shaft housing.

It holds the driveshaft slip yoke.

I also discovered a broken reverse drum to input shaft Bronze thrust washer.


So off to the internet I go to order a $4 part and $12 in shipping.

Ya Hoo, Miz