GQ 2.8 to 4.2 conversion

[Cyrusbilly]

Hi I'm in the process of doing a Rd28 to TD42T conversion and I have a couple of question to any who has done this conversion. Exactly how different are the engine mount measurements if possible. Can you use the the AC compressor from the RD28 on the TD42. The flanges on the drive shafts will the 4.11 TD diff flanges fit on the RD 4.6 diffs. Cheers in advance.any other advice would be great..

[Bloodyaussie]

Gday mate you need to head over to the intro section and say gday and tell us a bit about yourself before posting up questions. .. polite and all... Cheers

[Cyrusbilly]

Hi thanks for that, I have added an intro and look forward to exchanging info. In short live in Ballarat I have 97 GQ patrol at the moment have removed the RD28 and the TD42 T is ready to go in. My patrol has 4" lift, 33s, ARB bar work, rear locker, duel batteries and winch. Cheers for any help

[Clunk]

Welcome aboard mate and good luck with the install. I can't remember seeing any info on here about a rd28 to td42 conversion on here but that's not to say there isn't any info on it though

[sooty_10]

Welcome mate, I've done this conversion but in a GU so there may be some differences. First off the engine mount on the drivers side needs to be moved or modified forward a small amount, can't remember the measurements I got but I mainly trialled it and compared to my donor car etc.

The diff flanges are different, you can easily swap the pinion flange from the 4.1 to the 4.6 if your wanting to keep them. I did that to start with then went back to the 4.1 myself (4.3 would be ideal for me). I then used the td42 driveshaft etc. alternatively use the rd28 driveshaft and swap the t/case flange over (or the whole t/case if easier).

As for the aircon compressor I'm not sure at all I used the one on the TD42 so someone else will chime in no doubt.

[Cyrusbilly]

Thanks for that, I am going to put the motor in tomorrow I have read that the drivers side engine mount needs to be moved back I think 30 mm so I will go with that. Has anyone got any info on how to make up a plate so you don't have to cut the engine mounts. I have been told the cross members from the 2.8 bolt to the 4.2 gear box but move the motor to far back?
I will let you know how I go, I am surprised there is no one who has done this conversion on here.

[Cyrusbilly]

Ok gearbox and motor are in, no real issues I had to modify the engine mount and I will post pics, because it is GQ to GQ should be no other real issues.
I do need so pics of the TD 42 crsossmember to see if there are any differences, front drive shaft it close to cross member after fitting gearbox.
Need to replace AC compressor as the 2.8 compressor won't fit.
Now all I need to do is get the drive shaft modified and get her running.

[sooty_10]

It would be easier to swap the pinion flange IMO than modifying the drive shaft. Literally took me 10 mins to swap the flanges, need a big breaker bar extension though.

[Cyrusbilly]

Yeah the only problem don't have the flange just the drive shafts, can I use any flanges EG from TB42 with 4.1 diffs.
I wasn't sure if the flanges on the 4.2s where the same as the 4.6 from a RD28.
If they are easy all I have to do is find some

[dysonest]

how did u go with the conversion mate ?
what did u sort out for the tacho ?