Overdrive question

[64beam]

HI Forum,

The last couple of times I have been out in my Alpine, I have noticed that after a while of driving my overdrive starts to slip in both o/d 3rd and 4th (the overdrive is still engaged) . I had a look in my manual and there were a few things to check. Since I have owned my car, I have only changed the gearbox oil, but not the overdrive. I found the drain plug, but where is the fill point for the o/d and how do you get to it .

Thanks, Robin.

 

[skywords]

Robin
The OD and the gearbox share same oil. When you change the oil you have to drain the gearbox and the OD. They have separate drain plugs. The book calls for 30W oil. they fill at the gear box.

Are you sure it is still engaged and the safety switch is not causing it to disengage? This is happening to me with my Series II. If I bump the gear shift lever to the left it disengages. Needs adjustment, sometimes it unhooks by itself due to bumps in the road. I thought it was a serious problem at first.
Try moving the shift lever to the right and see what happens.

I have not owned an OD car very long. Someone else will be better at internal problems. Good luck.

Rick

 

[64beam]

Thanks for the reply Rick. It is definately not disengaging the o/d, its actually slipping. In the Haynes manual it tells you to drain the o/d separately, that is why I asked the question.

Regards, Robin.

 

[skywords]

Robin
It may have a worn cone. I would invest in the factory manual, there are very good reprints available from SS. I have not seen the Haynes so I can't judge it but I know the factory manual is very good. Some times having both is better.

Rick

 

[Jeff Scoville]

As a thought, could it be the clutch is slipping due to the extra load incurred with the OD active?
You might want to try going slow in a higher gear without the OD engaged and see if you can get it to slip, by trying to accelerate heavily, might save some head scratching.
Let us know.

 

[skywords]

Good thinking Jeff. That's why you get the big bucks

 

[jumpinjan]

I have noticed that after a while of driving my overdrive starts to slip

It's having low oil pressure, oil could be low or your pump is bad.

 

[64beam]

Hi Guys,

Thanks for your responses . I do have the Rootes workshop manuals so I will have a read through those. WSM 145 gives four possible problems for the o/d slip. On the old forum I also remember that the earlier gearboxes had a smaller capacity. Wht I say this is that I remember when I changed the gearbox oil, it only took about two litres where it should be about two and a half litres. This made me wonder if the o/d was filled separately. Can someone please confirm this .

Thank you, Robin.

 

[Paul Domoney]

Overdrive slip

Hi Robin
Did you ever sort out the problem with the overdrive slip?
I have the same problem and would welcome any suggestions.
Like you it happens after a while. The gearbox is full of oil.
Cheers Paul Domoney

 

[64beam]

Hi Paul,

I have not had the chance to sort out the overdrive problem yet, but I did change the oil in an attempt to rectify the issue. On my Alpine's most recent drive I was still getting slippage in 3rd overdrive with none in 4th overdrive. I have actually been contemplating a five speed conversion if they are similar in cost.

Regards, Robin.

 

[Wombat]

Robin,

Just a thought, there is a filter in the overdrive hydraulics. If that needs cleaning it might cause low oil pressure and slippage. Of course, my car does not have overdrive so I am probably on the wrong track altogether.

 

[64beam]

Robin,

Just a thought, there is a filter in the overdrive hydraulics. If that needs cleaning it might cause low oil pressure and slippage. Of course, my car does not have overdrive so I am probably on the wrong track altogether.

Hi Robert,

Where is the filter located? When I get my Alpine home (when I have time) I need to check some things out. I have my Dad's Tiger at the moment.

Regards, Robin.

 

[alpine1963]

Hello Robin,

I have this problem too. I just installed OD in my Series 3 from a Series V car. It ran like a champ for a couple of months and then after a two hour drive I downshifted while still in overdrive from 4th to 3rd and it felt like it was spinning on me without pulling the car good. I bumped it out of OD and it picked right up and pulled just fine. A couple of months after that I started getting the same problem in 4th gear so I filled it up with 30W oil and it has been shifted and pulling good in OD since. I would love to find out if this is truely an oil issue or not. I'll keep looking for future post to see what is brought to us.

Cheers,

Todd
1963 Series 3
Lexington, SC

 

[Wombat]

Robin

Just going by the illustrations in the parts book, it is behind a square plate on the left side if the OD. Plate is held on by 4 bolts. As I said before, I am overdrive-less so this is all guesswork and theory.

 

[Series3Scott]

Hello Robin,

I have this problem too. I just installed OD in my Series 3 from a Series V car. It ran like a champ for a couple of months and then after a two hour drive I downshifted while still in overdrive from 4th to 3rd and it felt like it was spinning on me without pulling the car good. I bumped it out of OD and it picked right up and pulled just fine. A couple of months after that I started getting the same problem in 4th gear so I filled it up with 30W oil and it has been shifted and pulling good in OD since. I would love to find out if this is truely an oil issue or not. I'll keep looking for future post to see what is brought to us.

Cheers,

Todd
1963 Series 3
Lexington, SC

Todd - I had the exact same issue last summer and decided to drain the oil and replace with a heavier oil - that did the trick.

 

[64beam]

Thanks for the latest replies. At the moment, I have 20W50 in my gearbox so I might drain it and try a slightly more viscous oil. Mechanically, would the heavier oil effect anything internally?

Thank you,

Regards, Robin.

 

[Wombat]

Robin

When I bought my SIV, the synchros were not real good until the car warmed up. I drained and refilled the gearbox with 20W50 and the problem vanished away. I put the cause down to the original oil being too thick (maybe 80W90 gear oil), but thinning a little as it warmed up. Might be a bit of a balancing act to find the right grade.

A good first step would be to have the overdrive pump pressure checked. This needs special tools and adapters, so you may need to search for a specialist. If the pressure is OK, that probably means worn cone clutches or other internal problems.

Again from my interpretation of the manual.

 

[64beam]

Hi Robert,

I have a guy in mind down in Victoria that may be able to help as well as some possible club contacts. Overdrives are not something for the novice, but I am hoping that the cones are not worn and only require an adjustment.

Regards, Robin.

 

[alpine_64]

Hi Robert,

I have a guy in mind down in Victoria that may be able to help as well as some possible club contacts. Overdrives are not something for the novice, but I am hoping that the cones are not worn and only require an adjustment.

Regards, Robin.

Rob,

If your OD is in trouble (and hope its not) i have a good condition OD unit if you are interested. Also if the guy you are thinking of is a certain J.Needham be careful, you will be up for big $ and a box that afterwards would be great for the track... maybe not the road

 

[64beam]

Rob,

If your OD is in trouble (and hope its not) i have a good condition OD unit if you are interested. Also if the guy you are thinking of is a certain J.Needham be careful, you will be up for big $ and a box that afterwards would be great for the track... maybe not the road

Hi Michael,

Bernie from the club knew of someone, but I'm not sure who that was. Maybe it was J. Needham, but he did say it would probably cost something similar to doing a 5 speed conversion. Even before I spoke with Bernie, I was'nt expecting it to be cheap. I will also keep in mind your offer.

Thank you,

Regards, Robin.