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MG TD TF 1500 - 5 Speed with 4.3

While I am quite happy with my 4.3 rear end conversion on my TD, I have been following the transmission threads with interest. My gear box is fine, but in the event I have to replace or rebuild, I have considered swapping for the Skyhook 210 conversion.

I "thought" I had read that this was not a great idea with the 4.3 rear end, but when checking the gear box ratios for both the standard TD-TF and the 210, they are about identical (except for the addred .8 5th gear on the 210). As they are virtually the same, what (if any) drawbacks would there be to using the 210 with the 4.3 rear end? Or did I misread or misinterpret something?

Thanks in advance

Larry
Larry Karpman

Larry:

I've gone for the 4.88 rear end with the Ford Sierra 5-speed from Autogear in England - with a 0.85 5th gear, that gives an effective final drive of 4.15, which with my tires gives about 3300 rpm at 60 mph. That's about at the torque peak, and I thought that was about best.

You might find that with a 4.30 diff and an 0.85 final drive, you'll be too far below the torque peak in fifth, and you might find yourself always in 4th.

Now - I'm still talking through my hat, as I won't know for a few months as to whether I'm right or horribly wrong. But you might want to think about whether you want to go any lower than 4.55

Just my two-bits worth,

Dave
Dave Jorgensen

I've got the 4.3 and the Skyhook 5 speed. I love the gearing. Not to happy with the clutch action though.
Could be smoother taking off in first.
Cheers,

Bob
R. K. (Bob) Jeffers

I had a 1953 mg td with a 4.3 rear end. Staring off was a little difficult. It would try to jump. At speed it was great.
Ralph Cacace

My 4.3 is great all through the gears and am sure it would take 'another' gear with ease...at least on flat roads, which is what we want if for?
gblawson (gordon)- TD#27667

I have been running a 3.9 diff with the stock gearbox on my TF for the past 13 years. This gives me about 20 mph per 1000 rpm which sits me at 3500rpm at our legal speed limit which is quite comfortable. It can tackle all the hills Wales and the Lake district can throw at it, although I do appreciate we do not have the kind of inclines you get in N.America.Only once have I had to drop to first gear and that was when baulked on a club run in Wales.
Ray
1954 TF 2884
Ray Lee

Bob Jeffers:

You said, "I've got the 4.3 and the Skyhook 5 speed. I love the gearing."

The info I'd like to have is your RPM in cruise, say at 60 in 5th gear, and do you have sufficient acceleration from that if needed, or if passing is desired without dropping down into 4th gear? Heh, passing? Never thought I'd be asking that about a TD :-)

Thanks

Larry
Larry Karpman

"Passing....?"... Who said anything about passing?
You would treat it just like the stock one, if you drop to 2000 rpm, you just shift down a gear.....if you get around 3200/3500 you shift up a gear!
gblawson (gordon)- TD#27667

Larry -- As I recall 60 is about 3200 revs. Yes there is enough acceleration in 5th gear. For passing I use 4th gear and boy do you get some funny looks when you pass a big gas guzzler.

Gordon has the shift points spot on. Down a gear at 2000, up a gear at 3200.

When I'm caravaning with others from our club I am usually at about 2700 revs. Which I seem to recall works out to around 50 MPH.

Hope this helps.
Cheers,

Bob
R. K. (Bob) Jeffers

Thanks Bob, exactly what I wanted to know.

Cheers

Larry
Larry Karpman

This thread was discussed between 22/01/2008 and 02/02/2008

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