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Cat d7e torque converter question

Cat d7e torque converter question

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DrewAbt
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Does anybody know the stall speed of the torque converter on a low horsepower D7e 48a. My new Dozer seems to slip a little too much imo at the TC. I checked the tranny for slip via the u joint and the u joint doesn't move when the torque is stalled. It seems to drive a little harder when it's warm and will spin the tracks in first gear but I can also stall it in first if I really stand on the brakes. (The brakes are very responsive).
So I believe that the torque converter is not pulling the motor down like it should. I think it is probably pulling the engine from full speed to maybe 850-900 rpm. It's no doubt grunting but not as much as it should.
Also my trans pressure is always on the very low end of the green section of the gauge. The previous operator said that CAT was made aware or this and they told him that it was acceptable.

So my question is is my torque converter within the range or is it slipping a little too much? If so how do I fix it?
Btw it shift very good and runs excellent. There is no slip at the steering clutches either. It's just the torque converter seems a little too soft.
Thanks again
Drew
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Mon, Jul 10, 2017 8:54 PM
Old Magnet
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What's the actual s/n of the machine. Specs vary.
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Mon, Jul 10, 2017 9:44 PM
DrewAbt
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Reply to Old Magnet:
What's the actual s/n of the machine. Specs vary.
75 E3. Military cat
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Mon, Jul 10, 2017 9:57 PM
DrewAbt
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Reply to DrewAbt:
75 E3. Military cat
Would the TC be considered weak if I can stall it in first gear (barely)?
BTW never seams to get too warm under normal use.
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Mon, Jul 10, 2017 10:01 PM
catsilver
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Reply to DrewAbt:
Would the TC be considered weak if I can stall it in first gear (barely)?
BTW never seams to get too warm under normal use.
It is quite normal to be able to stall the torque with the brakes in first gear, if it is not overheating and can spin the tracks in first, it is probably all within specs. If the outlet relief valve pressure is low due to excessive internal leakage, it will overheat.
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Mon, Jul 10, 2017 11:45 PM
Old Magnet
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Reply to DrewAbt:
Would the TC be considered weak if I can stall it in first gear (barely)?
BTW never seams to get too warm under normal use.
75E3 is equivalent to 48A6393 to 6882
Stall speed is 986 +/- 65 rpm
Full load & speed manifold pressure should be 25 in. hg.
At stall speed manifold pressure should be 24 in. hg.
High idle is 1335 rpm
Full Load is 1200 rpm
Low idle is 525 +/-10 rpm

Brakes should hold down to 2nd gear.
First gear should overdrive brakes.

Good drive in 3rd but high stall rpm (suspect torque converter)
Good drive in 3rd but low stall rpm (suspect engine, boost pressure is first check

Transmission pump pressure should be 300 to 330 psi
Check transmission lube pressure (end of the circuit), should be 9-15psi at high idle.
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Mon, Jul 10, 2017 11:48 PM
captainhowdy
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Reply to Old Magnet:
75E3 is equivalent to 48A6393 to 6882
Stall speed is 986 +/- 65 rpm
Full load & speed manifold pressure should be 25 in. hg.
At stall speed manifold pressure should be 24 in. hg.
High idle is 1335 rpm
Full Load is 1200 rpm
Low idle is 525 +/-10 rpm

Brakes should hold down to 2nd gear.
First gear should overdrive brakes.

Good drive in 3rd but high stall rpm (suspect torque converter)
Good drive in 3rd but low stall rpm (suspect engine, boost pressure is first check

Transmission pump pressure should be 300 to 330 psi
Check transmission lube pressure (end of the circuit), should be 9-15psi at high idle.
just sayin. i would check the air intake system from the pre cleaner all the way to the engine. i have seed mud wasps and oil residue build up restrict the intake before the air cleaner to just bigger than a pencil. usually will see smoke though but not always.
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Mon, Jul 10, 2017 11:57 PM
DrewAbt
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Reply to captainhowdy:
just sayin. i would check the air intake system from the pre cleaner all the way to the engine. i have seed mud wasps and oil residue build up restrict the intake before the air cleaner to just bigger than a pencil. usually will see smoke though but not always.
Two questions:
My trans dash gauge shows 250 psi...not 300. Can this be raised with an adjustment?

What is the fix for the torque if it is slipping a little too much?

Fwiw I don't think it's an engine problem. It was just rebuilt and has excellent power with no smoke. It doesn't seem like the TC is able to lug it like it should IMO. Then again maybe they don't lug too low with a torque converter.
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Tue, Jul 11, 2017 3:14 AM
catsilver
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Reply to DrewAbt:
Two questions:
My trans dash gauge shows 250 psi...not 300. Can this be raised with an adjustment?

What is the fix for the torque if it is slipping a little too much?

Fwiw I don't think it's an engine problem. It was just rebuilt and has excellent power with no smoke. It doesn't seem like the TC is able to lug it like it should IMO. Then again maybe they don't lug too low with a torque converter.
The engine will not lug below 985 rpm, which is converter stall speed. fit a decent gauge on top of the pump to check transmission pressure, don't rely completely on the gauge on the dash.
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Tue, Jul 11, 2017 3:39 AM
captainhowdy
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Reply to catsilver:
The engine will not lug below 985 rpm, which is converter stall speed. fit a decent gauge on top of the pump to check transmission pressure, don't rely completely on the gauge on the dash.
have you put a tach on the engine while stalling the TC with a warm system?
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Tue, Jul 11, 2017 3:42 AM
Old Magnet
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Reply to DrewAbt:
Two questions:
My trans dash gauge shows 250 psi...not 300. Can this be raised with an adjustment?

What is the fix for the torque if it is slipping a little too much?

Fwiw I don't think it's an engine problem. It was just rebuilt and has excellent power with no smoke. It doesn't seem like the TC is able to lug it like it should IMO. Then again maybe they don't lug too low with a torque converter.
Transmission pump pressure has to do with the condition of the pump and fluid supply. There is no adjustment.
Speed clutch pressure 310-330psi at the transmission is adjustable at the transmission pressure control valve.

Torque converter slippage has to do with internal clearances. There is no adjustment. Repairs amount to restoring tolerances by replacing worn parts (overhauling the torque converter). Might want to run torque converter leak test but usual symptoms of leakage is overheating and loss of power.
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Tue, Jul 11, 2017 3:42 AM
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