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[Shackeng]

After replacing the tthrust washer last year, the AR35 box on the TD has been fine until the last few days. Occasionally it behaves like a slipping clutch on a manual. Oil level and colour is fine. What could this be?

[Shackeng]

Any thoughts?

[Andy H]

Any obvious triggers? Is it repeatable or random?

- faulty solenoid?
- worn out friction material?
- insufficient oil pressure to actuate the clutches? (maybe a result of damage to the oil pump? )

[Shackeng]

Any obvious triggers? If worked hard and giving it beans.Is it repeatable or random? Yes and Yes

- faulty solenoid? Is this a symptom of a faulty solenoid?
- worn out friction material? Is this likely to occur?
- insufficient oil pressure to actuate the clutches? (maybe a result of damage to the oil pump? ) Would that give this effect?

Thanks

[Chazza12]

check its gearbox control unit, if the seal on the connector getting a good fit as water or condensation can get in and cause problems. speedo signal etc goes out and in to the unit for the ecu. it can make similar problems and be erratic. 

[Shackeng]

Can't say it is erratic, just that when it has been worked hard, it can behave just like a slipping clutch on a manual box.

[Doctor Gollum]

Sounds like clutches getting tired then

[Kevin Wood]

Yes, probably wear to the clutches or an oil pump problem not keeping them engaged, although I believe line pressure is monitored so it'd probably put it into limp home.

Brake band adjustment might be worth a try before condemning it.

[Shackeng]

Thanks guys, remind me where the clutches are, and how to adjust the brake band.

[Andy H]

Thanks guys, remind me where the clutches are, and how to adjust the brake band.

Does this help 

[Andy H]

I tried looking at the oil pressure in the project MV6 box this afternoon - hot engine, engine running and box in drive.

Looks as though 5 bar is the required pressure. Do you have any way of reading your gearbox ECU? I was thinking that a missing thrust washer might have allowed damage to occur to the pump 

[Shackeng]

Thanks Andy, useful diagram. I have the spare Carlton AR35 from which I could steal the clutch plates. Annoying as I could have done that while I had the box off to replace the thrust washer, and as I have said elsewhere, I don't want to do such heavy stuff anymore.

[Shackeng]

I tried looking at the oil pressure in the project MV6 box this afternoon - hot engine, engine running and box in drive.

Looks as though 5 bar is the required pressure. Do you have any way of reading your gearbox ECU? I was thinking that a missing thrust washer might have allowed damage to occur to the pump 

Unfortunately no, but I did have a failed thrust washer.

[RobG]

Thanks guys, remind me where the clutches are, and how to adjust the brake band.

When the sump is removed there is a dome held on with 3 or 4 bolts. Remove it and there is a threaded screw with a lock nut, release it then tighten the screw to 5nm torque, back off five turns and then tighten the lock nut, this sets the brake band. Replace the dome then it`s a gearbox re-fill

[Shackeng]

Thanks guys, remind me where the clutches are, and how to adjust the brake band.

When the sump is removed there is a dome held on with 3 or 4 bolts. Remove it and there is a threaded screw with a lock nut, release it then tighten the screw to 5nm torque, back off five turns and then tighten the lock nut, this sets the brake band. Replace the dome then it`s a gearbox re-fill

Thanks Rob, at least i can try that without removing the box. I assume its under the larger rear sump?