I've got a problem with my type RA. 5th gear has developed a bit of synchro crunch when changing up. I've changed the gear oil to fully synthetic (which it was filled with originaly,)with no improvement. Now depending on what is found when the box is out and split, I'm thinking of replacing the 5th gearset, but could be something as simple as a locknut backed off the pinion shaft a touch or whatever.
Anyways main point to the question, and appologies for rambling, (there I go doing it again) is;

I'm not sure what the 5th gear ratio is, but it rev/mph equates to about 3500/70 mph. This gives an indicated 150 mph at the 7500rpm.

Is it possible to up the ratio slightly, how would this effect speedometer calibration, where could I get the said gearset from and at what price?

Please help. As Yosser said "I'm desperate Dan"

Al

 

Hello Al.

unfortunately I dont think the 5th gear nut coming loose will give you syncro probs, usually just jumps out of gear........sounds like syncro/ hub problems . If your looking for someone to do the job then mail me, I know someone who does a good, reasonable priced job...

 

A few people here have swapped their 5th ratio in the RA box to the std WRX one.. drops revs in 5th approx 500 rpm. I just changed the whole box & diffs !! Car is now much better on motorway cruise. Before, approx 3100 @ 100 kph, now 2800 @ 100 kph.
- Mark.

 

It is basically impossible for that nut to come loose locked in four places plus very tight.

Try redline gearbox oil, I have had that fix a number of synchro problems. If that doesn't work you will be in for a synchro change.

Dan