P38A 2.5 torque converter stall speed

Does anyone know what the stall speed should be when testing the box mine was 1500rpm which seems low, read somewhere it should be around 2500rpm

Mine stalls at 2000rpm. 1999 2.5tdi.
Is it one of ashcrofts modified converters?

Would be a nightmare having it at 2500 on a Diesel.

2000 sounds right.

The 1800rpm "slipping the clutch" feeling is the TC sitting against its stall speed. However the stall speed varies a bit depending on torque input and thus throttle position. Higher torque, means a higher stall speed, simply due to the fluid mechanics inside the converter. The throttle position also determines whether the trans holds onto the gear your in, and thus lets the engine rev up beyond the stall, or it upshifts.

If your below the stall speed, and apply some throttle, the engine will tend to rev up to the stall speed and sit there. This effect boosts torque output, as the engines spinning faster and thus able to produce more torque anyway, and the slip in the converter gets used to amplify the torque further. Once speed in gear matches the stall speed, the engine revs will start to rise. At light throttle, the box will shift before or just as that happens.

Mark Piercy said:

Mine stalls at 2000rpm. 1999 2.5tdi.
Is it one of ashcrofts modified converters?

Click to expand...

It's just a standard converter and wouldnt go above 1500 with my foot on the brake and full throttle

Henry_b said:

Would be a nightmare having it at 2500 on a Diesel.

2000 sounds right.

The 1800rpm "slipping the clutch" feeling is the TC sitting against its stall speed. However the stall speed varies a bit depending on torque input and thus throttle position. Higher torque, means a higher stall speed, simply due to the fluid mechanics inside the converter. The throttle position also determines whether the trans holds onto the gear your in, and thus lets the engine rev up beyond the stall, or it upshifts.

If your below the stall speed, and apply some throttle, the engine will tend to rev up to the stall speed and sit there. This effect boosts torque output, as the engines spinning faster and thus able to produce more torque anyway, and the slip in the converter gets used to amplify the torque further. Once speed in gear matches the stall speed, the engine revs will start to rise. At light throttle, the box will shift before or just as that happens.

Click to expand...

It didnt shift at all just revved to 1500, it wont pull when trying to drive normally also, I can be foot flat to floor and doing 20mph

Ooer, just to confirm, is the engine revving high with or is it held back and limited to 1500rpm.
When not in gear does the engine rev freely like it should?

Mark Piercy said:

Ooer, just to confirm, is the engine revving high with or is it held back and limited to 1500rpm.
When not in gear does the engine rev freely like it should?

Click to expand...

Limited to 1500rpm when foot on the brake and in drive with throttle at full, when in neutral revs freely to the redline

Sounds about right for the small torque converter used on the diesel. Be aware not to hold full throttle for more than two or three seconds whilst testing.

Hi,

Just to make sure we are speaking about the same speed. To test this I should press the brakes, put on Drive, and then full throttle. And you say rev stay on 1500? I think mine will only stop on 3k.

But I will check tomorrow.

Mine is a P38 2.5 DSE.

Rgards,

Telmo