20VT 6 Speed Gearbox Swap

I don't know a massive amount about these cars, but give me a fiat fire and super fire engine and I basically know all the ins and outs of them inc gearboxes.

These are a new game for me so i'll try not to be testing.

My coupe currently has the later 5 speed gearbox, and i'm thinking along the similar lines of the fire engines here. But does the 6 speed allow for better economy as well as slightly raised top speed, or is it still placing the rev ranges at 70mph moderately high?

Thanks

X

Adding the 6 makes a huge difference mate!

I went from getting 390 to a tank to low 500's taking it real easy, 70mph is around 2.5/2.6 k revs on the six speed, and sitting at 50/60mph on b-roads also makes a huge economy difference there too, if you have a late 5 speed, it's basically a streight swap.

However same as with the centos... you do get slightly reduced steering lock! Best mod by a country mile I've put on my car! And always nice having an extra cog to play with

Why the change in steering lock? Are the drive shafts different?

the box is wider

Ah OK thanks Per

I have a feeling that a Plus / LE / VT6 has a slightly wider turning circle than a five-speed Coupe, as the rack is changed to cater for the wider gearbox. However, I had a 6 speed box fitted to my old Sprinty and didn't suffer any loss of steering lock

Pretty sure its a straight replacement for any 5 speed 20VT with the later type gearchange.

Can also be fitted to early-type 20vts, but it will need the gearchange mechanism, cables and lever as well

Yep, totally right

Was your old sprinty an early or late 5 speed? I wasn't aware that LE / plus and 6's had a different rack. My porto is a late 5, and im positive it has reduced lock since I had the 6 fitted?

Not sure but don't you have to change the heatshield etc to fit the 6 speed gearchange instead of the 5 speed?

Interesting, I may debate on doing this one in the near future then.

Thanks

X

If youre 5 speed coupe has air con you have to move the dryer canister as the 6 speed box rubs against it and will wear a hole in it --- happened to me

Good advice!
I suppose most late Coupes have AC. Does it affect the How-To for gearbox removal..? (The "twist-drop"-version) The piping's close to the box..

Just swapped.
When trying to get to 6th gear I can't find it.. Seems too close between 4th and reverse, so it's possible I'd get to 6th if I lift the reverse lever?

Someone else had this problem?

I also had that problem........
Might sound strange , but in trying to find out what was causing it .............it sorted itself ,and that was over 12 years ago ,box been in and out several times , and now had a totally different rebuilt box fitted last year ,problem has never appeared again !
But when I think about it ,they developed the first 'short shift' on my car at the same time so it was maybe that ,that was the cause of my problem ( Barbz did the work when he worked for Barry )

Ok but is it something that might need a little tweaking to the gearstick mechanism, or is a Shortshift the only solution?

Per - you will probably find that it simply needs some adjustment of the cables

Can you get reverse?

yup i`d agree with that,doubt it`s anything to do with the box or fitment,should be just a case of cable adjustment

At the end of the day, it seems it's not actually a fully "straight swap"..

Seems the reverse-stop/lock on a sixspeeder is slightly different (or my gearlever is VERY worn?) so - you need to grind the gearstick a mm or so, for it to move sideways far enough.
So after a little grinding and greasing everything felt as std (and new, as my new box only done 40000km's, instead of my Coupe's 260000km's).
And motorway revs are down with 500rpm, very nice.





Finally, after a weekends work I could swap the Richbrook knob top!



We had to lower the subframe slightly as a LHD Coupe has the brakebooster on the left side.. Ouch.
Also the AC pipes were in grave danger but we found we could loosen the AC filter assembly and move the two pipes up and out of the way enough.

Oh, and the plastic protection panel in the left wheel arch had to be cut somewhat too to not foul the end of the box.

Well done Per a mod well worth doing -- less noise ,less fuel used, less wear and rear, and another gear to play with too , glad you sorted it out

thanks! Yeah it feels fantastic and almost surreal to have this extra gear.
(bad news were my inner CV joint rubbers were completely shot..)

This looks like a thread hijack, but I hope my experiences from this weekend helps Todger!

This is something I'd be interested in doing. How much did the 6 speed box run you then?

You mean how much it cost? 4500skr from a friend, or about 470euro. Cheap I know..

Ask your friend if he's got another one won't you...?!

Sorry that was the one.. but I see them on ebay now and again.

Is the 6 speed box capable of taking higher powered coupes just as well as the 5?

Something i would like to do, as much as i love the second-third gear run with the 5 speeder; 10-110 in one gear change, being a daily drive i could do with the lower fuel consumption.

How much do 6speeders usually go for in the UK with the linkage?

Having finally done my 6 speed conversion, I seem to have lost 5th and 6th.

I have the later gearstick setup and an LE box.

Are they the same as the seicento's in that there is an adjuster in the cable?

Thanks

X

Difficult to describe in words, but there's an adjuster on the selector mechanism - loosen a 12(?) mm nyloc nut which allows an arm to move a little backwards & forwards

To answer an earlier question, the six-speed box will handle big power, but not as well as the very early 5 speed - my current box is whining in 3rd and 6th, so needs a new set of bearings (which I've already bought - just need to have them fitted). I've been a bit unlucky though, as my previous six speed box lasted over 150,000 miles until I blew it apart on the startline at Santa Pod

Found it, will adjust shortly.

Couple of small things to address but all seems good.

One thing I do want to check though, the clutch pedal feels like I'm pressing nothing at all, and engages almost instantly when raising your foot.

Is that normal after a clutch change on these?

Thanks

X

Yes, it's OK......

Only asking as before it used to bite halfway up the pedal, now it's about a quarter of the way up.

Lost count how many times I've nearly stalled it.

Thanks

X

As it's new there's more meat on the friction plate so less travel required on the pedal before it bites.