C20LET/F28 conversion

[ant]

My question: I currently don't have anything from the gear nob to the F28... which way should I go for the selector setup and what should I source?


What I have done: I have fitted the ATB diff and yeah that was fun... not... it took a few goes getting all the selectors in the right position but in the end we had 6 forward and 1 reverse.

I have read up about using the ABS ring and sensor and I will be using a Speedo Corrector kit same as I fitted to my Opel http://www.jaycar.com.au/productView.asp?ID=KC5435

Having the LET now in it and I have changed the firewall to take the internal gear selection setup to allow for the big exhaust as it was hanging down way to low and as a daily driver every speed bump would have been a nightmare.

[man with astra,s]

Re: C20LET/F28 conversion

i used a 16 vavle astra gear stick and rod / and the f28 linkage set up

[ant]

Re: C20LET/F28 conversion

I don'r even have the F28 Linkage setup either... was wondering if the straight setup like the Harry Hockly one is the go and does it utilise the original hole in the firewall?

[Roger]

Re: C20LET/F28 conversion

the harry hockley/quaife one, has to be used without the linkage, otherwise it's reversed. If you want to use it anyway, you need to adjust the rod (as the F28 doesn't have a turret, thanks BenH).
And to prevent you get to sharp angles with the rod and helicopter connectors, you will need to drill another hole to get the rod through.

See my topic here: http://www.astra-mk2.com/forum/showt...Racing-shifter

I wanted to get another shifter also.

Now i'm thinking about making one myselve, and use the linkage.

[ant]

Re: C20LET/F28 conversion

If I had a complete F28 Calibra gear slick, rods and selector for a 4wd Cali will that all fit into the Mk2 16V shell?

Is the gear stick unit the same or similar size to the 16V one? or should I stick to Mk2 16V setup?

I just have the option of getting a complete "gear nob to gearbox" setup from a wreck here in Australia.

[Harvey]

Re: C20LET/F28 conversion

Ant the cage where the gearstick fits is the same on the Cally 4wd as on the Astra mk2 16v. You will find the rod is slightly different as it will be bent a little differently for each car and may be longer/shorter. I'm sure a few tweaks here and there and it'll fit a treat.

If you have the Corsa C over there (Barina is it still?) the non ABS versions have an impulse amp and you can take a speed feed directly off a single front ABS sensor. Wiring for the impulse amp, which is 15 impulses off a 29 tooth ABS ring) is as follows; In1 - abs sensor, In2 - abs sensor, Out - speed signal to EPAS, 15 - switched ignition 12v+, 31 – Earth. The abs sensor wiring can be wired either way polarity does not matter. They are in engine bay fuse box with the other relays and look like the picture below. You can use these for EPAS so the auto sensitivity works correctly offering more assistance at low speeds and less to non at high.

[ant]

Re: C20LET/F28 conversion

Thanks Harvey Yeah I just got a reply back from the guy and he indeed has the complete gear knob to box setup so he is going to give it to me this weekend.

He also has the linkage bracket that bolts onto the top of the gearbox and I assume it sits onto of the Tbox... (got this pic from MIG forums) the one on the left he has.



I don't have the STD rear gearbox mount with the linkage bracket because it was a 8v GTE... so I was just going to make a L bracket off the box between the mount and box to hold the Linkage bracket is it's position or for that matter just weld a bracket onto the mount. Do you have a pic of a F28 with this in position so I can get a reference point? This is what I made on the weekend.



So the the relay looking orange thing... this is the impulse amp? Ok sounds easy enough... it does sound like the way to go though. Thanks heaps for that... I should just be able to get one from the GM 09185826 then off ebay maybe. If I have both ABS sensors in the car should I connect both? any benefit?

Oh and I just check I have both 29 tooth and some 40 odd tooth ringed drive shafts but do I need to match the sensor to the ring number or are the sensor's the same for both systems?

[Harvey]

Re: C20LET/F28 conversion

Hi Ant, yes I can get you a picture of the F28 with the proper pivot mount fitted. Will try and remember to do it this evening, gearbox wrestling here we come. You only need run one ABS sensor with the impulse amp but you will need the earlier 29 tooth ABS ring as this is what the Corsa C, Astra G and Zafira A use as all non-ABS models have the the impulse amp for the speedo feed. ABS models take the speedo feed directly from the ABS unit. I believe it doesn't matter on the sensor as long as it can pick-up from the ABS ring.

[Harvey]

Re: C20LET/F28 conversion

Sorry didn't get chance last night. What car is the F28 going into, is it a mk2 Astra? I only ask as you can use a Daewoo nexia rear mount (same as the GTE 16v) and drill and tap the F28 to accept this. Fitting guide here http://www.daewootech.com/docs/f28_fwd/. I will get you some pictures of the propper mount for the gearlinkage pivot this evening.

[Harvey]

Re: C20LET/F28 conversion

Loads of pictures for you Ant.

My F28 spares box with cracked casing you can see the three holes that require drilling and tapping to fit the mk2 mount.


Nexia mount, same as mk2 16v and holes that require drilling/tapping.


How the Cav/Cally rear mount fits.


F28 original pivot linkage. The two vertical bolts got into the top of the transfer box and the horizontal bolt goes into the top of the three bolts holes on the F28.





I'll be using an Astra mk3 small block pivot setup with a few mods for the wifes V6 project.


One thing I have noticed is the pivot centre point is 8mm more to the n/s on the Nexia/mk2 16v mount to the right.



Pivot on the Astra mk3 is the same location as the F28 setup.


Astra mk3 pivot mount part no.


If you need anymore pictures or measurements let me know.

[Black Magic]

Re: C20LET/F28 conversion

ant, why are you using the speedo corrector kit from the ABS? is it cos ur speedo isn't working? if that's the case, I put on the black plastic ring gear on my dif, (see above) although its a bit late for you now, now that you've put your ATB in



if its just for a correct speed, then ignore above

I too have 8v chassis, with F28 box. the 8v shifter, just doesn't cut the mustard for me. so this post is somewhat interesting to me. I know ive got to drill the hole through the bulkhead, I have the stick shift & housing as well as linkage on my old astra, together with the 16v mount.

so I was unsure myself how to tackle this, as that was on an F18cr box, not F28. & using the above stuff, I noticed that the rear engine mount, rear bush didn't align properly & was somewhat slightly offset. slight differences between the 8v/16v chassis. ( MAY be what Harveys talking about )

Harvey, could you do us a list, on what is exactly needed & from what car?

• 16V shifter
• Daewoo Nexia rear engine mount
• F28 Linkage from Calibra??

[Harvey]

Re: C20LET/F28 conversion

Someone please correct me if I’m wrong as my F28 is not going into a mk2 but I believe you will require the following:
Astra mk2 or Daewoo Nexia rear mount with 8mm spacers where it mates to the F28.
Cavalier or Calibra F28 pivot linkage.
Astra mk2 or mk2 linkage bar from pivot linkage to gearbox selector.

I might be talking crud but from what I’ve read this is what is required but you might be able to mod something together with the stock mk2 16v linkage and/or an Astra mk3 linkage.

As I said above if you require anymore pictures just let me know.

[ant]

Re: C20LET/F28 conversion

Blackmagic the F28 I'm fitting doesn't have the speedo drive hole machined in the case and to do that would have been a real pain.

Harvey thanks the pics show me exactly what I was after... the forward hole bolts into the top mount hole and so the 2 other bolts would be into the transfer... I guess the only question is the angle of the top of the transfer box... I'd assume it is 90deg to the gearbox rear face if that makes sense.

Very interesting about the angle of the Nexia as I was going to get one but because I have the F28 linkage bracket I am going to mod the STD 8v mount to take the Aluminum F28 linkage bracket thus why I am interested in the angle of the top of the 4WD transfer case.

Ok started the Mod after picking up the parts.



I drilled out the linkage bracket and this is my delama of what angle the bracket should be... rotating it a few deg changes the distance a fair bit.



Notched the 8v Bracket to fit up against the box square







Sliced trough the bracket and started to fit the Linkage bracket.



Once I work out the angle of the bracket I will weld a plate onto the mount with 2 tapped holes to fix it.



One other question though. The rubber bush that connects to the gearbox selector rod from the linkage is flogged out... can I get a replacement rubber bush?

[Harvey]

Re: C20LET/F28 conversion

Does this help Ant? The tx box sits square to the rear of the F28. Pics of my bro-in-laws F28 with locked transfer box off his Cavalier Turbo. I helped the other week and took some pics as he replaced the rear crank seal and gearbox to transfer box seal. It’s a right old lump when trying to refit as the tx box has to be bolted to the F28 to fit.

[ant]

Re: C20LET/F28 conversion

Thanks but yeah not quite... just need a pic from the passenger side looking at the angle of the bracket in relation to the gearbox housing.



So in red looking along here and maybe backing it up with in yellow a measurement here.

I do have access to a 4wd Calibra... I will ring him in the morning and see if can have a look and take my flexible inspection camera to have a look.