98 V70XC AWD to FWD conversion

Post by **div4scpro** » 24 Apr 2015, 08:44

On the above listed car the cost to repair all the AWD components was prohibitive. The question is I have a 50-42LE from a 97 850NA with super low miles and excellent condition. I know they have different final drive ratios and there are motor mount considerations. Questions are:
1. If I swap the 97 transmission control module and the TCU along with the 97 transmission should that preclude any code or shift point problems?
2. If I choose to retain the 98 transmission with the bevel gear removed, has anyone come up with a reliable modification issue.
3. If I leave the bevel gear on, not my first choice, will a OEM 2000 angled flange downpipe and dual exhaust fit?

Carboncopy · Post by **Carboncopy** » 24 Apr 2015, 08:55

I think you can literally just take the drive shaft off and leave everything else original without issue, but other more experienced people can comment more on this. I would not really worry about a tranny swap, my XC has been FWD only for at least 5 years and has never really had any issues (previous owner got rid of the driveshaft and from what I can see did not change anything else).

Blockpartie · Post by **Blockpartie** » 24 Apr 2015, 09:02

3) Downpipe won't fit. '98 components take up more room e.g. there is none left for the '00 downpipe.
Rear exhaust section will fit.

2) For a reliable modification issue I recommend adding water to your ATF. Very quick and easy way to introduce issues.

Just stick with the angle gear or force the collar to stay in the trans itself. The '98 transmission is not prone to failure.

1) In theorie: Yes. However check the wiring first. In addition you might want to check the axles, some N/A cars came with smaller diameter axles. Those aren't ideal for a turbo car.

Post by **div4scpro** » 25 Apr 2015, 13:45

is it the bevel gear which prevents the turbo angle flange and 2000 downpipe from fitting or other components?
not real sure what you mean by the recommendation to add water to the ATF fluid?
knew that axle diameters would come into play, had that factored in.
thanks for the reply.

lookforjoe · Post by **lookforjoe** » 25 Apr 2015, 21:40

No can do on the ECU/TCU swap. Only 98 ECU/TCU can be used in a 98.

'00 DP is ANGLE FLANGED, as you described. Yours is not. Unless you plan to install a ANGLE FLANGE turbo (or at least hotside), that won't work either. You will find that the AG will also be in the way, since '00 has a shorter overall length AG casing than 98-00, by at least an inch.

Post by **div4scpro** » 30 Apr 2015, 10:37

angle flange is going in as part of the build. my ignorance, not sure about AG abbreviation means.

Post by **jimmy57** » 30 Apr 2015, 10:47

Can't do N/A trans in turbo due to different final drive ratio. The TCM will set codes. The tcm can't be swapped as it isn't mapped for the load signal values a turbo will send to tcm for shift regulation.

Car parts exchange has been made just about as hard to do as finding a liver donor.

Post by **renns** » 01 May 2015, 10:53

Did you have transmission problems currently? If not, just leave the AWD transmission in place, and remove propshaft alone, or propshaft and bevel gearbox. I chose to remove both, as I had to seal up some leaking turbo lines as well, and it's much easier with the bevel gearbox removed. The splined drive collar between the bevel gearbox and tranmission must stay in the transmission to keep the transmission properly sealed. Here's the procedure I used:

- Remove bevel gearbox and splined collar.
- Clean collar and mating splines on transmission carefully.
- Apply loctite to splines, and insert into transmission.
- Fabricate and attach retaining bracket to prevent collar from walking out of transmission.

The last step might have been a waste of time, as there is no sign of any movement of the collar, and I've driven the car 70k miles since.

Here's a pic of the assembly:

and one of the retaining bracket: