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MY OWN OD PROBLEMS FREE WHEELING IN OD

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mster50 Silver Member Mike Sterling/A
Zanesville, OH, USA   USA
1980 MG MGB
Thanks everyone, you guys really come to a persons rescue. From reading all the comments, it sounds like one or two times in reverse with OD and your done. I have done that. The one time I forgot it was in OD and tried reverse I tried it several times wondering why it would not move the car very well until I noticed it was in OD. Oh well.
Every gasket on the engine, trans and rear end leaks. The engine is coming out this winter to fix the leaks. I might send the unit away to be looked at. I might get a real 5spd.

Thanks again everyone.

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Thunder Bay, ON, Canada   CAN
1971 MG MGB
I might be talking out of turn, I don't think that reversing with the OD engaged will cause any major issues as the speeds you are reversing in aren't enough to build up the appropriate pressure to do any damage. I agree it's best practise not to do that, but should cause a major issue unless you get up to speed.

It also sounds like you have the opposite problem to what you are saying.

You say the RPM jump 600 or so? Wouldn't that indicate that the OD disengaging when you hit the gas, and slipping in when you let off?

mster50 Silver Member Mike Sterling/A
Zanesville, OH, USA   USA
1980 MG MGB
In reply to # 3608774 by Kurt Breitsprecher I might be talking out of turn, I don't think that reversing with the OD engaged will cause any major issues as the speeds you are reversing in aren't enough to build up the appropriate pressure to do any damage. I agree it's best practise not to do that, but should cause a major issue unless you get up to speed.

It also sounds like you have the opposite problem to what you are saying.

You say the RPM jump 600 or so? Wouldn't that indicate that the OD disengaging when you hit the gas, and slipping in when you let off?

I am not going to definitively say no to anything, but I want to say no.

Here is a more precise description of what is happening. While driving along at say 70mph. That is about 4,000 rpms (just guessing don't hold me to these numbers). Click it into OD, rpms drop to about 3,200 or 3,300 or so. Continue driving knowing you are in OD and no slippage or free wheeling. Up comes a corner you need to slow down for. Let off the gas to use engine braking instead of the brakes. Instead of the rpms starting at 3,300 and dropping as the speed drops, it will instantly drop to 2,500 or 2,600 with no braking effect at all. You can rev the engine a little and let back off and it will go back to the 2,500 or 2,600 rpm. Something has to be dragging the engine up to this lower rpm, but I don't know what that would be. Finally rev it back up to the 3,300 rpm you will feel it catch something it fell out of, it feels like the OD unit not 4th gear. It is now back in 4th and OD. You do not have to use the shifter to get it to catch. Before everything warms up and starts slipping or free wheeling there is plenty of engine braking. Then as it warms you loose engine braking in 1st and 2nd first, then 3rd and then finally 4th and all gears.

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mster50 Silver Member Mike Sterling/A
Zanesville, OH, USA   USA
1980 MG MGB
In reply to # 3608890 by mster50
In reply to # 3608774 by Kurt Breitsprecher I might be talking out of turn, I don't think that reversing with the OD engaged will cause any major issues as the speeds you are reversing in aren't enough to build up the appropriate pressure to do any damage. I agree it's best practise not to do that, but should cause a major issue unless you get up to speed.

It also sounds like you have the opposite problem to what you are saying.

You say the RPM jump 600 or so? Wouldn't that indicate that the OD disengaging when you hit the gas, and slipping in when you let off?

I am not going to definitively say no to anything, but I want to say no.

Here is a more precise description of what is happening. While driving along at say 70mph. That is about 4,000 rpms (just guessing don't hold me to these numbers). Click it into OD, rpms drop to about 3,200 or 3,300 or so. Continue driving knowing you are in OD and no slippage or free wheeling. Up comes a corner you need to slow down for. Let off the gas to use engine braking instead of the brakes. Instead of the rpms starting at 3,300 and dropping as the speed drops, it will instantly drop to 2,500 or 2,600 with no braking effect at all. You can rev the engine a little and let back off and it will go back to the 2,500 or 2,600 rpm. Something has to be dragging the engine up to this lower rpm, but I don't know what that would be. Finally rev it back up to the 3,300 rpm you will feel it catch something it fell out of, it feels like the OD unit not 4th gear. It is now back in 4th and OD. You do not have to use the shifter to get it to catch. Before everything warms up and starts slipping or free wheeling there is plenty of engine braking. Then as it warms you loose engine braking in 1st and 2nd first, then 3rd and then finally 4th and all gears.

I had this almost back wards. I drove the car yesterday and tested the OD unit. I did not check it when it was cold. When it was warm when it is out or not in OD it will free wheel as described above in all four gears. In OD it works great in all four gears. No free wheeling, good engine braking, no slipping. I still think it slipped in OD and reverse, but I am not testing that again.

Is that something different that be fixed in car or does it still need to come out and be serviced?

How much are these transmissions with OD worth? How much is a typical cost to repair an OD with the symptoms like mine has?

I want a real 5 or 6 SPD.

ohlord Avatar
ohlord Gold Member Rob C
North of Seattle, N.W., USA   USA
1957 Land Rover Series I "EYEYIYI"
1971 MG MGB
1971 MG MGB "Bedouin 2"
Fix it under a grand
Use a 5 speed rivergate kit and trans over $1500 even more if the 280zx trans needs rebuilding.
Miata 5 speed over $3000



"I'm a long way gone down this wild road I'm on
It's gonna take me where I'm bound
It's a long way around"



"These are the days that must happen to you"

RD2 Radar/ Electronic Warfare Technician
Vietnam 1969-1972

geezer Avatar
geezer Silver Member charles durning
Magee, MS, USA   USA
1958 MG Magnette ZB "Chick Magnette (sold)"
1967 Morris Minor 1000 Saloon (2-door) "Marvin"
1974 MG MGB GT
If your main box is OK I have a spare reman OD section.



Who's version of right are we talking about? When you get 10 LBC owners in a room you'll get 12 different answers.

mster50 Silver Member Mike Sterling/A
Zanesville, OH, USA   USA
1980 MG MGB
In reply to # 3615298 by geezer If your main box is OK I have a spare reman OD section.

How much?

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mster50 Silver Member Mike Sterling/A
Zanesville, OH, USA   USA
1980 MG MGB
Sounds like it still needs to come out and be serviced or probably rebuilt, is that correct?

Depending on the price of rebuilding mine or a rebuilt OD unit, I think I would like to put the repair money toward a swap for a real 5 SPD.
Would that be sound thinking?

I have two 5 SPDs and 4.3L V6s from Chevy trucks. I would like to make the best of the two work in a swap, but I read that 90 degree V6s and V8s are difficult swaps because of engine width.

A question about forum etiquette.
Do I need to go to the swap forums and start a topic about trans swaps?

geezer Avatar
geezer Silver Member charles durning
Magee, MS, USA   USA
1958 MG Magnette ZB "Chick Magnette (sold)"
1967 Morris Minor 1000 Saloon (2-door) "Marvin"
1974 MG MGB GT
Mike,

The OD trans is a nice fit for the MGB. OTOH when mine shoots craps a 5 speed will go back in.

On the swaps you might get better help from the swap or performance forums. Though a 90 degree swap is doable, there will be more room around the engine with a 60 degree engine. Personally I don't care for a crowded engine bay. I'm not versed on all of the possible 5 speed swaps, there may be someone out there who can supply parts to adapt your 5 speeds to the B engine. It could happen I just don't know who.



Who's version of right are we talking about? When you get 10 LBC owners in a room you'll get 12 different answers.

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ohlord Avatar
ohlord Gold Member Rob C
North of Seattle, N.W., USA   USA
1957 Land Rover Series I "EYEYIYI"
1971 MG MGB
1971 MG MGB "Bedouin 2"
Wrong engine and wrong 5 speeds
The engine is a lot of work with little support and the truck 5 speed isn't the right unit.
There are far more suitable choices
60v6 3.4
302 sbf
Any of the BOPR
MATED TO A T-5 5 speed of the correct length.
Good luck thumbs up
Visit the darkside

In reply to # 3615791 by mster50 Sounds like it still needs to come out and be serviced or probably rebuilt, is that correct?

Depending on the price of rebuilding mine or a rebuilt OD unit, I think I would like to put the repair money toward a swap for a real 5 SPD.
Would that be sound thinking?

I have two 5 SPDs and 4.3L V6s from Chevy trucks. I would like to make the best of the two work in a swap, but I read that 90 degree V6s and V8s are difficult swaps because of engine width.

A question about forum etiquette.
Do I need to go to the swap forums and start a topic about trans swaps?



"I'm a long way gone down this wild road I'm on
It's gonna take me where I'm bound
It's a long way around"



"These are the days that must happen to you"

RD2 Radar/ Electronic Warfare Technician
Vietnam 1969-1972


Attachments:
Old Blue 275H.P. V6 swap sidepipe nascar exhaust rear profile.JPG    40.6 KB
Old Blue 275H.P. V6 swap sidepipe nascar exhaust  rear profile.JPG

mster50 Silver Member Mike Sterling/A
Zanesville, OH, USA   USA
1980 MG MGB
I have seen it recommended elsewhere and you recommend the Small block Ford. When working with Hot Rods, Small block Chevy's were more popular because of the aftermarket and they were one inch shorter in length. This allowed them to fit early Fords without modifying the firewall. Both are 90 degree V8s. Why the Ford over the Chevy?



Edited 2 time(s). Last edit at 2017-10-25 03:49 PM by mster50.

geezer Avatar
geezer Silver Member charles durning
Magee, MS, USA   USA
1958 MG Magnette ZB "Chick Magnette (sold)"
1967 Morris Minor 1000 Saloon (2-door) "Marvin"
1974 MG MGB GT
One reason for the Ford in the MGB is the distributor is in the front. Can move the engine closer to the firewall. It is also narrower than the SBC.



Who's version of right are we talking about? When you get 10 LBC owners in a room you'll get 12 different answers.

mster50 Silver Member Mike Sterling/A
Zanesville, OH, USA   USA
1980 MG MGB
In reply to # 3616428 by geezer One reason for the Ford in the MGB is the distributor is in the front. Can move the engine closer to the firewall. It is also narrower than the SBC.

Distributor in front, yes. Narrower?

http://www.carnut.com/specs/engdim.html

This says both are 22 inches wide. I know the Chevy should be fractionally wider. It has a taller deck height. If you are moving out and up, when you go farther up it should also be farther out or wider.

Does that little amount make a big difference?

67motorcat Avatar
67motorcat Silver Member Steve O
Pinehurst, NC, USA   USA
1967 MG MGB
Mike if you really want to go with a 5 speed with no fuss thumbs up

https://www.vitesse-ltd.com/products/vitmgb251

mster50 Silver Member Mike Sterling/A
Zanesville, OH, USA   USA
1980 MG MGB
In reply to # 3616552 by 67motorcat Mike if you really want to go with a 5 speed with no fuss thumbs up

https://www.vitesse-ltd.com/products/vitmgb251

If your staying with the MG engine this looks the best way to go. But that is a lot of money.

Thank you for the tip, Mike.

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