52 replies to this topic

[Oreo931]

I'm doing some research for my manual swap, and there is a lot of conflicting info out there on the two transmissions H vs L.

Can someone clear up the differences between the two trannys?

Which has longer gears, which has shorter gears? Which will get better hwy gas mileage? etc etc.

Thanks in advance.

I saw this PDF: http://www.volvoclub...cations1997.pdf ... but it only has the gear ratios for M56 and M56L2... I don't know what those are

[850 LongBeach]

The M56H has a longer first and second gear
The M56L has shorter first and second

M56 has a longer final drive ratio

Other than that they are exactly the same (Except minor mechanical differences, IE plastic shifter forks on the Ls)

IN SHORT

M56h=better low end
M56l=better top end

[yangotang]

top end and low end refer to power curves.

short and tall refer to gearing.

M56L = taller
M56H = shorter

[Oreo931]

Good info. Thanks.

In terms of durability, I read that the H's stand up better to more power. Is this just hearsay, or is there a basis for it? I'm not going to be keeping the stock turbo for long, and I want to make sure that I do this once, and do it right. If the L is going to die more quickly then I will forget about it.

[yangotang]

OrEo931, on 19 October 2009 - 04:18 AM, said:

Good info. Thanks.

In terms of durability, I read that the H's stand up better to more power. Is this just hearsay, or is there a basis for it? I'm not going to be keeping the stock turbo for long, and I want to make sure that I do this once, and do it right. If the L is going to die more quickly then I will forget about it.

heresay.

i'm gonna pull a L apart soon to see if the forks are indeed plastic.

[850 LongBeach]

OrEo931, on 19 October 2009 - 04:18 AM, said:

Good info. Thanks.

In terms of durability, I read that the H's stand up better to more power. Is this just hearsay, or is there a basis for it? I'm not going to be keeping the stock turbo for long, and I want to make sure that I do this once, and do it right. If the L is going to die more quickly then I will forget about it.

Power? It depends...300-350 whp shouldnt be a problem at all on the L's and lord knows Ive seen higher on them!

[shanehutton]

I would really like to get to the bottom of this as well. I know that the L has shorter gearing and the H has higher gearing but I want to know if there is any strength difference. I don't need a high top speed and I don't mind losing some gas milage for better acceleration so I am leaning towards the L. That said, I am going to be putting it through a lot at the track so I would like to know if it is weaker than an H.

Somebody pull an L apart and see what's inside. I find it hard to believe that Yohan hasn't taken a peek inside one...

[850 LongBeach]

You have it backwards...

H is faster acceleration
L is better top end

[shanehutton]

I am pretty sure it is the other way around. I am pretty sure that at any given speed the engine will be revving higher with the L than the H.

[oRange855]

The L that grenaded in the wagon did not have plastic forks

[yangotang]

shanehutton, on 19 October 2009 - 04:40 AM, said:

I am pretty sure it is the other way around. I am pretty sure that at any given speed the engine will be revving higher with the L than the H.

wrong.

[shanehutton]

Really. I always assumed that the L was shorter because the early NA needed as much help as it could in acceleration. My whole world just flipped upside down.

[850 LongBeach]

shanehutton, on 19 October 2009 - 04:40 AM, said:

I am pretty sure it is the other way around. I am pretty sure that at any given speed the engine will be revving higher with the L than the H.

Wrong

shanehutton, on 19 October 2009 - 04:44 AM, said:

Really. I always assumed that the L was shorter because the early NA needed as much help as it could in acceleration. My whole world just flipped upside down.

Its ok let me flip you back over...

Buy an L kit for 500$ cheaper than an H and call it a day!

[lookforjoe]

yangotang, on 19 October 2009 - 04:13 AM, said:

top end and low end refer to power curves.

short and tall refer to gearing.

M56L = taller
M56H = shorter

850 LongBeach, on 19 October 2009 - 04:12 AM, said:

IN SHORT

M56h=better low end
M56l=better top end

I have no idea which trans does which. The Volvo spec would provide the final drive ratios for the cars with each version trans.

Be that as it may, you're both saying the same thing, not worth arguing about


Shorter gearing will give you more low end pull, taller gearing gives you longer legs.

Either way, it's the Differential (Final Drive) Ratio that will determine tall/short.

[EricF]

lookforjoe, on 19 October 2009 - 12:36 PM, said:

I have no idea which trans does which.

It's funny because I don't think he does either

Quote

Either way, it's the Differential (Final Drive) Ratio that will determine tall/short.

Yup...

Furthermore..

Quote

Gear ratios (M56L):
1st - 3.38
2nd - 1.90
3rd - 1.19
4th - 0.87
5th - 0.70
Reverse - 2.99

Gear ratios (M56H):
1st - 3.07
2nd - 1.77
3rd - 1.19
4th - 0.87
5th - 0.70
Reverse - 2.99

The M56H has a more even gear spread with a smaller gap from second to third gear. That is why it is more preferred.. I don't think strength is an issue, and have never seen a single case on this website that would make me think otherwise.

The M56H is available in North America with just the 4.00:1 final drive ratio. The M56L is most common with the 3.77:1 from my understanding/experience, and this makes it's gear spread a bit wider. It is also found with a 4.00:1 final drive though.

So, if it's an L with the 4.00 final drive, it will have shorter first and second gears than the H, and the rest will be the same. If it's a 3.77 final drive, first and second will still be shorter albeit by the tiniest of margins. Third, fourth, and fifth will all be longer gears, and your cruising RPM in fifth will be lower than with the H.

Hopefully this clears up any confusion.

Bottom line: M56H has a more even gear spread, and first and second gear are longer regardless of what M56L it's being compared to (talking about the N. American 4.00 final drive M56H, the European 4.45 is another story ).

[shanehutton]

Thanks Eric. That helps a lot.
Any idea if the final drive info is on the case anywhere?

[ozzimark]

Eric, are you positive that the 5th gear in the L is the same 0.70 that the H has? I'm not sure if the L2 indicates something different from the L, but it has a 0.65 5th gear

[EricF]

shanehutton, on 19 October 2009 - 01:33 PM, said:

Thanks Eric. That helps a lot.
Any idea if the final drive info is on the case anywhere?

It will be on the info tag where M56H or M56L is indicated.

ozzimark, on 19 October 2009 - 01:51 PM, said:

Eric, are you positive that the 5th gear in the L is the same 0.70 that the H has? I'm not sure if the L2 indicates something different from the L, but it has a 0.65 5th gear

I really haven't heard of an L2 here in NA, maybe they have them somewhere in some model?

[Oreo931]

Eric to the rescue

Thanks man!

[ErikS]

This may also help a bit. The open differential is the weakest link, is it not? That's one of the reasons for having a quaife lsd is important not only for the traction if I'm not mistaken.