Mods 3 - Onyx Firefox kit car

Rod and I set off for Hullavington, near Chippenham in Wiltshire at 8.00am, me in the Firefox and Rod in his car, which was loaded up with tools, spares, fuel etc., etc. We arrived in plenty of time and parked next to Richard and Stan Grove?s blue Firefox. It was a dry and bright day, but bitterly cold with a biting wind straight from Siberia. After signing on, I took my car to the noise testing area. Thankfully, with the extra silencer, the noise level was well within the limit at only 93dB. At 9.30am, we attended the drivers? briefing where the various rule and regulations were explained.

I?d already booked a session with an instructor which was money well spent. After several laps with the instructor (Erling Jenson) as passenger, we pulled into the pits for a debrief. Apparently, I was making all the usual mistakes a track beginner makes ? turning into corners far too early, missing apexes, not using the entire width of the track and there were several occasions when the car ?wasn?t doing anything?. Erling explained that on a track, the car should always be working ? either accelerating, braking or cornering. I vowed to improve matters and we went back out for some more laps. Although it was impossible to talk to each other on track, Erling used hand signals to get his points across. At the end of the session, Erling said there had been a big improvement. He also said the next thing I should work on was the position of my hands on the steering wheel, as they had been ?all over the place?. If my speed and lines are correct, I should only need to apply a maximum of half a turn of the steering wheel in either direction, which can be achieved by keeping my hands in the same place on the wheel (roughly at the ?quarter to three? position) and crossing my arms. I tried this out in the afternoon sessions ? it came quite naturally and it does work well. Another improvement.

All in all, a very successful day. I enjoyed myself and learnt a lot. Between us, Rod and I covered 120 miles on the track and I did another 35 miles travelling to and from the venue. The car didn?t miss a beat all day.

I didn?t want to have the extra silencer permanently stuck out the back of the car (and Chris wants it back soon), so I?ve removed it and refitted the front bullet silencer and the rear shiny tail pipe.

Another airfield day with Motorsport Events. This time the venue was Keevil, near Trowbridge in Wiltshire. A good course layout on a very smooth and clean surface, coupled with warm dry weather and plenty of track time made for another very enjoyable day. With the front silencer fitted instead of the extra rear one, the car was even quieter at 91dB.

The trailer for the car was finished just in time for this event, so I was able to give the Onyx a good thrashing without worrying about getting home at the end of the day. I needn't have worried though because the car behaved impeccably, apart from a minor hiccup with a gear linkage joint.

I must have been trying harder this time as I managed my first spin. Arriving a bit too quickly at a fast right-hander, I felt the rear end starting to slide. Being a novice, I panicked and backed off the throttle. Big mistake! The car span several times, demolishing a line of cones. One of the cones got wedged between the back of the engine and the subframe, causing the session to be red flagged while we struggled to remove the cone. Very embarrassing. Back in the pits, the only damage was a bent rear mudguard, which was soon knocked back into shape and a missing front number plate (it was only held on with Velcro), which was recovered at lunchtime.

Later in the day, at the same corner, I felt the back end starting to let go again. This time I got off the brakes, applied a bit more throttle and the car sorted itself out for me. I'm sure I heard the cones breathe a sigh of relief.

Just like at Hullavington back in March (where does the time go?), Richard and Stan Grove brought their Onyx. Richard kindly took me out for a ride in his car and showed me just how fast a Firefox can go with more power, more grip and, most importantly, more skill behind the wheel.

Despite Keevil being a shorter circuit than Hullavington, we did another 120 miles on track between us. We also suffered the first mechanical problem - every time we tried to engage reverse gear, the lower gear selector rod jumped off its ball joint. This wasn't too serious, as reverse isn't needed very often on an airfield, but it will have to be sorted before the car's next outing. I had noticed that the gear change was getting rather sloppy, so I suspect the two are related.

Several pictures from Keevil are on the Gallery page.

Inspecting the gear linkage revealed that the plastic ball joint that kept popping off had split. The cause seemed to be excessive wear in the upper gear selector shaft. Instead of just rotating as it should, there was a lot of front to rear movement and quite a lot of twisting, causing the ball joint to operate at angles it couldn't cope with. There's nothing externally that can adjusted or replaced to reduce this movement, so I think a replacement gearbox is called for. While the gearbox is out, I'll try to make a quick-shift to reduce the movement of the gear lever and I'll also experiment with the clutch actuating arm, to lower the biting point of the clutch and hopefully make its engagement a bit more progressive.

The replacement gearbox - just £45 from Andy at APS. It's a R65U version (the U supposedly stands for uprated, but no one seems to know exactly what's been improved) from a 1997 114 Gta and has done 42,000 miles. This one has a 3.538:1 final drive ratio, instead of the 3.765:1 currently in the car. I think this slightly taller ratio will suit the lighter Firefox perfectly. I'm going to replace the drive shaft oil seals, the input shaft oil seal and the clutch release arm bushes before fitting this 'box. Hopefully, I can source those during the week, so it can all go back together next weekend.

The upper gear selector arm. The selector rod usually fits on the ball stud below the arrowed rivet.

A new hole was drilled 25mm inboard of the existing ball joint. Grinding off the rivet to remove the ball stud revealed an 8mm diameter hole, which is perfect for the rod ends I'll be using.

The rod end in place. Actually, it will be fitted under the arm, but you get the idea. If for any reason this set up doesn't work, the rod end can be bolted in the outboard hole, which will return things to normal.

Removing the ball stud from the selector arm on the subframe revealed another 8mm hole. Thank you Rover.

This is roughly how the linkage will look when it's all bolted back in place. Tomorrow's job is to remove the old 'box.

Working on this car really is easy. Undoing two nuts and bolts removes the entire nose cone/bonnet, allowing good access to everything. Being front wheel drive, the engine can stay where it is and after removing the hubs complete with drive shafts, the gearbox just pulls off the side.

With the gearbox removed, I can turn my attention to improving the lower gear selector linkage.

The split plastic ball joint. These joints are no longer available separately and the local MG/Rover dealer wants nearly £30 for this rod assembly. Sod that - the 8mm rod ends I'm using are only a fiver each.

The standard and modified lower selector arms. I'm using 8mm spring washers as spacers to allow the rod to move in all directions. Because of the limited space between the arm and the subframe, I've cut the bolt off flush with the top of the nyloc.

The inner end of the new lower linkage rod. Another ball stud removed and replaced with a rod end.

The new seals and bushes were collected this morning and fitted in the evening. It took less than half an hour to change them all.

With the newer gearbox fitted, I ran the car through the gears while still up on axle stands. The combination of a much newer and tighter gearbox and my mods to the linkages made a huge difference to the gear change quality - it's now much crisper and with a lot less lever travel. After congratulating myself on a job well done, I lowered the car to the ground. While removing one of the front axle stands I noticed a drop of fluid falling. Closer inspection revealed it to be coming from the bottom of the bell housing. A quick sniff proved that it was EP gearbox oil. Oh Sh*t! My immediate thought that it must be coming from the oil seal that I'd replaced - there's no other way for gearbox oil to get into the bell housing area. Perhaps it was the wrong seal, perhaps it was faulty or maybe I'd put in in wrong or damaged it when refitting the gearbox to the engine.

Whatever the cause, there was only one thing to do - the 'box had to come out again. I tore into the job and had it out in less than two hours. What I found was not good news...

The oil wasn't coming from the suspected seal, but from a crack in the bell housing. When I renewed the clutch actuating shaft bushes, the release arm was stuck fast to the shaft. I supported the arm on two pieces of steel bar so that the shaft could be knocked down through. I thought that the bottom of the shaft was going down through the hole in the lower bush mounting, but the shaft must have been resting on the mounting itself. This resulted in all my hammering going straight onto the aluminium casting, causing it to crack. Unfortunately, I didn't notice this before putting the gearbox back in.

I've phoned a few of the local Rover breakers, to find another gearbox. Andy at APS didn't have one, but Dean at Allcars is breaking a 1998 Rover 114 Ascot SE with just 22,000 miles on it. He wants £60 for the 'box and it'll be out by Friday, so I can fit it next weekend.

It might be possible to weld or fill the crack, or even swap the bell housings over, but all these options will need the gearbox to be stripped. I suspect the labour cost at a gearbox specialist will cost more than the gearbox is worth. If so, these will both have to go to the tip. I know losing £45 isn't the end of the world, but wasting time and money annoys me. If the next gearbox also has a stuck clutch arm, my next trip will be to Machine Mart to buy a puller. I won't make the same mistake again.

Another gearbox, another stuck clutch arm. This time, instead of just beating the crap out of it, I heated the arm and used my new puller (less than £20 from Machine Mart) to remove it. No damage this time.

While I was at Machine Mart, I bought a new "Oil Suction Pump" for less than £7. Basically a large metal syringe, it replaces one I've had for years that was getting rather tired. Considering the amount of time and mess it saves when refilling gearboxes, every garage should have one.

The clutch arm on the earlier gearbox (pictured here on the right) is not the same as the ones on the later gearboxes. The later arms are approximately 15mm longer and have the hole for the roll pin at a slightly different angle. These two differences should mean that the clutch pedal action will be lighter, slightly more progressive and have a lower biting point, which are all things I want to achieve.

After fitting the new clutch pivot shaft bushes, I transferred the new input shaft sleeve/seal and the modified lower selector arm to the latest gearbox, then did the grinding and drilling of the top selector arm. After a quick clean, the 'box is now ready to go in on Sunday.

I'm going to keep both the old gearboxes for now. I might even attempt to swap the bell housings myself, but that will have to wait until Winter. I finally got rid of the old 414 block and dismantled the engine stand, so I've got some storage space again.

I'm a lot happier than I was last Sunday. Having fitted the latest gearbox, I donned my crash helmet and took the car on a lengthy test drive. Not being a great football fan, I left the house at 7.10pm and enjoyed the almost deserted roads. All the mods and changes are a total success - the gear shift is much shorter and more positive and the clutch action is greatly improved. I drove around for quite a while going up and down through the gears just for the hell of it. When I got bored with that, I practised some standing starts. The taller gearing and the different clutch arm meant I could consistently get away more quickly, with less tendency to spin the wheels or bog the engine down. There's no clutch judder anymore either, which apparently was caused by the worn clutch pivot shaft bushes. Time for a beer!