TR4 Overdrive Reverse Gear Stopped Working - Just Whirs ?

[dingle]

Lebro is correct, the unidirectional clutch functions only in the forward gears when the OD is disengaged. In reverse, the sliding clutch transmits power to the annulus.

Worn linings could cause the slippage, but usually the front or OD portion of the linings wear out first. The return springs do weaken with time and cause slow disengagement of the OD and slipping in reverse.

Berry

[AlanT]

Lets hope its the springs because this is a fairly easy fix.

[saggy]

Hi Alan,

is that easy for you ? or easy for me ?

At the moment all I can say is that I can't see but I can hear the switch and solenoid are working.

 

May I ask again... "In the TR owners handbook it says.... "move the lever UP to engage overdrive and down to release it"

Others say they have it the other about. Is the handbook known to be wrong? What is the correct answer here for in/out up/down please ? ? ? as I would like to get it working as Triumph sent them through the factory gates.

Many thanks. S

[JBRoberts]

Hi Saggy

 

I checked my lever which is on the right of my steering column (left hand drive) when UP the OD is off and when the lever is DOWN my OD is on ( solenoid clicked and pulled up). The fella who built my Gearbox confirmed this

 

Tks JB

[peejay4A]

The handbook for my 4A makes no mention of up or down for overdrive operation. It's a repro though.

[graeme]

Pete,

 

Should be at the bottom right of page 8 even in the repro.

 

Cheers

 

Graeme

[Lebro]

It does not matter which way the switch works, the main thing to check is that the gearbox isolation switches are preventing O/D from being switched in

unless in 2nd, 3rd, or top gear, & definatley NOT reverse.

 

Bob.

[peejay4A]

Well roger me sideways Graeme, there it is at the bottom of page 8. That's strange because if I was to position the switch so that it works that way it would be pointing down at my right knee when off and I don't fancy that. It's a repro switch with only two contacts, not a changeover switch, so I can't just rewire it. As I'm so used to the way it is I think it'll stay as it is.

[MikeF]

It does not matter which way the switch works, the main thing to check is that the gearbox isolation switches are preventing O/D from being switched in

unless in 2nd, 3rd, or top gear, & definatley NOT reverse.



Bob.
-----------------
Do that by selecting gears and or turning the ignition on/off. You should hear appropriate clonks or none as the relay/solenoid operates or not according to what you are doing.
e.g. IN 2 3 or4 should clonk as you turn ignition on, In first and reverse nothing with ignition on off, but with ignition on should hear drop out when moving from any gear though neutral and another clonk when selecting any gear except 1st reverse,

Mike

[AlanT]

Most TR owners seem able to get gboxes in/out somehow.

Splitting the OD from the gearbox is simple.

 

The first thing you come to is the bridges and the springs. You can put in new springs easily. Its just a spanner job.

 

Further in the OD gets tricky. Some kind of unusual tool is required to handle the accumulator and pump.

The tail bearings are tight as hell. At least mine were.

 

So of all the many things that could want fixing in an OD, springs are one of the easiest.

And you can't do any stupid stuff like fitting it backwards.

 

Of course you do have to get at the wretched thing.

 

You might be able to get the OD off and out without removing the gbox.

Don't know if you could get it back though.

Edited April 5, 2014 by AlanT

[saggy]

Alan, Mike and Bob,

Very many thanks for your time and advice - much appreciated.

Will investigate properly tomorrow.

Best regards, Saggy

[JBRoberts]

Folks

 

Here is an update on my problem. I changed the oil in my box to Red Line MT 90 then worked with my gearbox rebuilder who had me loosen up the solenoid plunger lever and wiggle the shaft on the other side. I did this about 15 times. Topped up the gearbox. Tested the solenoid to make sure it was going off and on and it did. Took the car for a long run and got the gearbox nice and hot. Tested for reverse gear and it was fine - no slipping whirring or anything ! So not sure what was wrong but all seems good now.

 

Now to run it in for 500 miles so I can open her up

 

Tks for everyone's help on this...JB

[saggy]

Right and here's my update!

 

Awful weather to-day so ran up garden to shed. Went through Mike's 'routine'....

 

Lever up - no switch/solenoid noises in any gear with ignition on or off.

Lever down - switch/solenoid noises clearly heard going in/out of 2nd, 3rd, 4th but nothing in 1st/reverse.

 

Conclusion - everything working as it should but, like Pete's, the column lever or other wiring is wired differently to handbook so I was on the assumption that it was working differently to how it actually was. Is the handbook incorrect?

 

However, it now puzzles me why I haven't had a driveway covered with shards of metal (as per the doom-sayers) from attempting to reverse whilst I obviously had O/D lever in engaged position in error before?

Also, although it still just whirs (with the O/D properly disengaged this time!) whilst feeding in the clutch, if I drop the clutch smartly I do get reverse. Could it be that either worn out linings or feeble springs (or both) has saved me??

I could try topping up oil. Would 'wiggling the shaft of my solenoid plunger' (!) really serve any practical purpose?

Thank you for sticking with me on this - I've learnt something everything day!

Saggy

[AlanT]

You have been "saved" by the interlock switck on the gbox breaking the circuit even though you had the lever in the on position.

Thats why the gbox has these switches.