4 Speed O/D conversion to automatic (SE5a)

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Jpwill7675
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4 Speed O/D conversion to automatic (SE5a)

Post by Jpwill7675 » Thu Oct 03, 2019 12:13 pm

Hi - I can see that a popular choice is to swap the auto gearbox for a 4 speed manual with overdrive. Has anyone on here gone the reverse route? Just wondering how difficult/practical it is.

I am finding the the pedal box very small fro my size 10's. That, a stiff clutch and no power steering are making town driving less relaxing than I had hoped. Just thinking about future options at the moment.

Thanks for any feedback,

Jim


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4 Speed O/D conversion to automatic (SE5a)

Post by peter freeman » Thu Oct 03, 2019 12:30 pm

Power steering can be done with EPAS the clutch can be lightened by use of a servo ( as per brakes ) if you do want to go with the auto go for the 4 speed one as per the MB as the 3 sped auto is terrible IMO.



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4 Speed O/D conversion to automatic (SE5a)

Post by Roger Pennington » Thu Oct 03, 2019 12:57 pm

Well, all I can say is I've driven the mulberry car, with a standard C3 box, since 1983 and it's fantastic. The only small criticism I would have is that if you're going to cruise on the motorway at 80 all day, it's not as high geared - but then if you're going to cruise like that you don't need an autobox!


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scimjim
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4 Speed O/D conversion to automatic (SE5a)

Post by scimjim » Thu Oct 03, 2019 1:35 pm

Yep, I commuted for years in a 6a auto - only eventually converted to manual overdrive because it came with a hot Rew engine.

Off the top of my head, you’ll need

Auto box inc gearstick/linkage, vacuum pipe, kickdown cable, flex plate and torque converter
Remove spigot bearing in crank
Pedal box
Auto throttle cable/kickdown bracket
Change spacer on gearbox mount (can’t remember if you add or remove one)
Propshaft (can’t remember if the 6a auto prop fits the 6a overdrive with sliding flange but obviously won’t fit the earlier bolted flange?)
The overdrive loom unplugs by the wiper motor and the auto (inhibit/reverse switch) plugs straight in but I think you need an additional inhibit relay.


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4 Speed O/D conversion to automatic (SE5a)

Post by scimjim » Thu Oct 03, 2019 1:41 pm

Given the choice, I’d go the extra mile and fit the 4 speed though, it is a better box IMHO.


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SECURE DRY STORAGE FOR YOUR SCIMITAR

Current: SE5 (8Ball), TI SS1 (snotty), 1600 SS1 (G97), 1600 SS1 (C686CCR), 2.5TD SE5a (diesel 5a), 6 x random other SS1s.
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4 Speed O/D conversion to automatic (SE5a)

Post by AJL Electronics » Thu Oct 03, 2019 2:04 pm

Agree with Jim. C3 is an excellent gearbox, but the A4LD makes it nicer at speed. There are probably far more C3 gearboxes and bits available than A4LD though, due to those strange folk who throw them out and go back down to a pudding stirrer!


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4 Speed O/D conversion to automatic (SE5a)

Post by rebel alliance » Thu Oct 03, 2019 2:26 pm

I had a 5a Auto 30 years ago and a 6a manual .Sold the 5a and after a bump the 6a went in the garden (still there)...So 2015 acquired another 6a manual and a 5a manual, problem arose on driving that home i found the pedal box so narrow i needed to do something before i drove it again.So i removed the foot rest and dog legged the clutch pedal by i think 30 mm...As the car already had pas it now drives like a mini 6a. I may have read on here that a different size clutch master can make the clutch lighter ?
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Jpwill7675
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4 Speed O/D conversion to automatic (SE5a)

Post by Jpwill7675 » Sat Oct 05, 2019 2:57 pm

Thanks for the feedback and suggestions every one. Much appreciated.


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4 Speed O/D conversion to automatic (SE5a)

Post by henspeed » Thu Oct 17, 2019 12:37 pm

I have an auto 5a that id be interested in doing a manual swap on.
we could do a mutual exchange, but we could not be much further apart geographically in the UK if we tried



Jpwill7675
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4 Speed O/D conversion to automatic (SE5a)

Post by Jpwill7675 » Sat Oct 26, 2019 9:26 am

Thanks for the suggestion. I have now sourced another car with an automatic gearbox.


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