[ripsnort40]

Hi,
I have a lovely condition 2006 156 JTS which I have just rebuilt the cylinder head of & it's running really sweet. The power is very linear & it pulls really well. Hardly surprising that it feels better as half the valves were not sealing & it was probably about 50% clogged with soot/gunge too. It's done 116k miles & this was first time the engine had been apart. Some evidence of cam wear, but bores were "too good". Still crosshatching visible. Guessing thats why these things use oil.

As a daily car it is great with 2 exceptions. Cheap aftermarket lowered suspension which I will replace with something nearer stock when I can. The second item is the gearing. Wow, is that 5th gear low. I've done some research & understand that the diesels & some later cars used the GM F40 6 speed found in Vectra, Signum & Saabs. I also understand that there are 2 variants of that box, the earlier MT2 & the later MU9. In respect of ratios, the earlier box is very tall with overdrive 4th, fifth & sixth. In fact it gives an appx roadspeed equivalent in 4th to my current 5 speed's top gear. I did some geek maths & although it would make a phenomenal cruiser, they may be a bit too tall for everyday enjoyment. The MU9 from 2006 however has a 5th that is slightly taller than my 5th, but has a usefully longer 6th on top. So from a ratios perspective seems the best of both worlds.

Of course on paper that's fine, but what would be useful is understanding whether the bellhousing & driveshafts will work & whether there is a particular donor car that would be a best match to fit the JTS engine & the 156 fixings. Gearbox/final drive to body fixings I can fabricate, but if there are major clearance issues or customs driveshafts required or if there are terminal mismatches, I don't know & can't seem to find on searches.

Be really pleased for any advice which may help on this. The boxes are so cheap secondhand that I am tempted just to get one to offer up, but if I know what donor car is best suited it could save me a lot of hassle.

Many thanks in advance.
Mark N 2006 156 2.0 JTS

 

[sprint_veloce]

Most TS/JTS 6 speed conversions are done using the 166 TS box, which almost bolts on with a few complications - a search on here should find details. Not sure if a F40 box would work at all, and you'd have to get one from a petrol car as diesel gearing with max engine revs at say 4500 rather than 7000 like your JTS is going to be a bit hopeless.

 

[Gertie]

Yes Sprint_Veloce is right, the 166 TS box is the easiest to start with, but you will also need: the side shafts, the half shaft, the half shaft carrier (that also has the alternator and power steering pump carriers on) AND the sump - yes the carrier interfere with the stub sump extension at the back.

The other alternative is the Diesel box with V6 internals. Again you'll need the 1.9 diesel or 2.5 side shafts , diesel half shaft, diesel half shaft carrier (spliced with the TS alternator and power steering pump carriers) AND a modified sump

Read about my effort on my race car:
http://www.alfaowner.com/Forum/sout...rofeo-phakisa-as-a-newbie-3.html#post14738762

EDIT: My experience is with the C630 boxes, I do not know how much effort the F40 box is to swap ratios or get compatible half shafts or side shafts.

as Sprint said, you cannot use straight diesel ratios as at highway speeds, you will have NO torque in your upper gears you'll end up using only up to 4th. 5th and 6th will be useless - top end is 400km/h in 6th at 7000 rpm for the C630 diesel ratio.

 

[Gertie]

Oh yes I forgot to mention that you need to remember the slave cylinder is concentric and you'll have to change to the external slave, but that is no biggy, the master cylinder keeps up,, it took a while for it to bleed through properly though.

Also you need the 6 speed cables and selector to get the right throw

 

[ripsnort40]

Oh yes I forgot to mention that you need to remember the slave cylinder is concentric and you'll have to change to the external slave, but that is no biggy, the master cylinder keeps up,, it took a while for it to bleed through properly though.

Also you need the 6 speed cables and selector to get the right throw

Many thanks for the detailed response Gertie & Sprint. You've saved me wasting time & effort on what was probably a blind alley. Anything is possible, but have to question the worth! I will look to the 166 box & ancilliaries, but suspect that I will just live with the issue. I bought the car as a cheap but character runaround for £600 so it only owes me less than £1k even with the various repairs & minor improvements I've made.

All the very best,
Mark

 

[Gertie]

There are two more options you can investigate:

The Selespeed's 5th gear it longer than the normal TS (and by deduction the JTS too?) You can replace the 5th gear in the TS gearbox with have to change the whole set like in the C630 (V6) box.

Then even longer gearing is the 1990's Fiat UNO Turbo that shared the same 5 speed gearbox platform as the TS - You'll use the internals only

 

[David C]

The Selespeed's 5th gear it longer than the normal TS

Are you sure?
Selespeed had a lower 1st gear, so a bigger gap between 1st & 2nd, but I thought all the other gears were the same.

 

[symon]

Just a thought, has your car got the standard sized wheels and tyres?

If they have been fitted with tyres/wheels of a smaller rolling radius it will lower the overall gearing.

Not by a massive amount, but it could be noticeable.

 

[Gertie]

Are you sure?
Selespeed had a lower 1st gear, so a bigger gap between 1st & 2nd, but I thought all the other gears were the same.

I also had it that 1st is shorter (3.909 vs 3.545), and thought 5th was longer ... But confirming the info now it is in fact the final drive that differs: 56/15 (3.733) vs 57/16 (3.563):

FIAT ePER

http://www.goo-net-exchange.com/catalog/ALFA_ROMEO__ALFA_156/10015407/
http://www.goo-net-exchange.com/catalog/ALFA_ROMEO__ALFA_156/9002448/

 

[Gertie]

The very early 147 1.9 JTD (8V) 74kw used the same gearbox: 63/20 (3.15) final drive

Gearbox: 1st 3.909 : 1, 2nd 2.238 : 1, 3rd 1.444 : 1, 4th 1.029 : 1, 5th 0.767 : 1, 6th -, Reverse 3.545 : 1, Final drive ratio 3.150 : 1

 

[typos1]

Hi,
I've done some research & understand that the diesels & some later cars used the GM F40 6 speed found in Vectra, Signum & Saabs. I also understand that there are 2 variants of that box, the earlier MT2 & the later MU9. In respect of ratios, the earlier box is very tall with overdrive 4th, fifth & sixth. In fact it gives an appx roadspeed equivalent in 4th to my current 5 speed's top gear. I did some geek maths & although it would make a phenomenal cruiser, they may be a bit too tall for everyday enjoyment. The MU9 from 2006 however has a 5th that is slightly taller than my 5th, but has a usefully longer 6th on top. So from a ratios perspective seems the best of both worlds.

Have you driven a car with the F40 box ? ! Its a horrid gearbox with an awful gear change, believe me, you DONT want one of those in your Alfa, plus theyre also made of chocolate and fail all the time. The 166 box is the way to go.

 

[scottyf]

The six speed in the 166 ts overall ratios are not that different to the five speed. I know as my ts had the 5 speed box and I think the difference because the final drive ratio is lower would be 50rpm difference for any given speed.

The 6 speed is a nice to have but I find myself skipping alot of gears because it really doesn't need that many in reality.