I've been playing around with an engine that has an auto gearbox. I picked the engine up from the previous owner saying they did not know what condition it was in.

I'm testing the drivetrain on the engine so I leave the box in Neutral and turn the engine over and the uni joints don't turn - cool.
I put the box in any other gear, turn the engine over and the unit joints move around, but I apply pressure to them and I can hold them and they don't move. I'm guessing it should move as if it was driving.

Any ideas what could be wrong?

other info: It's a Morris Mini Matic engine (not Rover) and I am using a battery to turn the engine over.

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Justin

At cranking speed, surely an auto will allow the driveshafts to be stopped, else how else would you sit at lights with the engine idling?

The torque converter won't approach stall speed (when it's starting to transfer all the power to the gears) until the motor is at a speed above idle. (Unless of course the AP auto is way different from other types?)

The only real way to test the box would seem to me to be with the motor running up to normal driving revs.

We have now exhausted my knowledge of auto boxes!

Cheers, Pottsy

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Smile Up at The Trucks!

Pottsy is correct ^^^, an AP box works like most other autoboxes in this respect.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Thankyou Pottsy & drmini - that makes sense.

So, at idle there should be no drive but at 2,000RPM (or there abouts) it should be doing something. I shal reassemble the carbs/exhaust and fire the beast up.

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Justin

Idle speed from memory (when my Matic was one) is 650 rpm.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

The weak point in the auto box is the forward clutch. If the motor is out I would replace it or at least inspect it before going to the effort of fitting it to a car.
Another good idea is to check the oil pressure at the gearbox with a gauge following the procedure in the manual. If the pressures are low in certain tests it can show a fault.

They are a real easy box to work on. Parts are still available in the UK.

Thanks for your answers Morris1100.
I have 4 complete auto engines (of varying sizes) out of cars that I was wanting to test to see what they need. Your input is cool - thanks.

I sure hope so!

Any ideas where from - any links available?

Thanks

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Justin

http://www.jpat.co.uk/

Enjoy...

I bought gaskets and the forward clutch plates for the AP auto in Parramatta (Sydney)
from http://www.pnc.com.au/~mmworld/

Not sure what other parts he carries, maybe worth a call.
But that jpat link would be best if you need a whole bunch of stuff.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I used Jpat for my auto box stuff, they are real cheap (considering) and very quick. Got heaps of stuff. Highly recommended.

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88 Rover 1.3i "Reggie"
99 Rover 1.3i “Grover”
12 Mini Cooper S "The shitter"
17 Mini Clubman JCW “Noddy”