28. New Gearbox and Oil Cooler

This one is about the work we have done in the last 4 weeks to bring the thread up to date before our trip to Croft tomorrow.

Had a few jobs to do between track days which then led to a couple of problems.

First up is the new gearbox install. Went for the gripper diff with the 4.54 final drive set up for circuit racing (120nm preload, can’t remember the ramp angles). Seems like the only down side is the need to service them every year so will be sending it back down to Mark every winter.

Before completing removing the engine decided to do a compression test. Surprisingly good for an engine with 110k miles of it. All cylinders very close to each other.

With the simplified engine bay (no pas, no air con, no battery etc) its rather easy just to pull the whole engine and gearbox out, couple hour job if you’re not rushing.

And the old gearbox off. This was actually a 089 box, so had the long final drive so will be really noticing the 4.54 drive in the new box.

Engine and new gearbox then back in. Engine balance plate makes it pretty easy and feeling rather smug about the small lifting hole I added to the custom coil pack relocating bracket.

Then the first problem, LHS driveshaft was too long. Was tight up against the gripper cv joint cup so had two options shorten the current shaft or find another. Both the original shaft and J&R shafts were the same length (655mm) so ended up ordering a phase 1 GKN shaft which is 640mm (actually measures 645 in reality) which seems to fit perfectly. So the trip to Croft will see if this one works or not. If it does another one will be being ordered as a spare.

Will also take the current one to CPS Drivelink which is local to be cut down, pretty sure cutting and joining it and only losing 10mm with the friction welding will be possibly.

The next over the top item we bought was a Mocal Laminova oil cooler, meant to be much more efficient than the radiator oil coolers and all seems to make much more sense to us so thought it was worth the extra couple hundred quid. Still up for debate whether I prefer driving the Clio or buying new shiny parts, close run thing I would say.

Seemed to line up pretty well with the mounting face to the engine/gearbox so made a bracket to mount the cooler direct to the engine, whether this is the best way to do it I don’t know yet but it certainly seemed the neatest.

I did tidy the bracket up and gave it a couple coats of paint before putting it back on. Time will tell if we need to add a half restrictor in there but safer to run without one for a day and see how we get on. Coolant runs pretty constant between 71-74 so seems like we have a bit of room to play with compared to the oil at above 120.

So time to fire up again and also run into the second problem. Fired up no bother but then would cut out after 5 seconds or so after not being able to idle. This is what it sounded like.

Went right round the doors with this one, tried everything. Checked injectors, spark plugs, sensors, fuel pump etc, all pretty easy to do with the ECUMaster kit I have to say. ECU was showing a trigger error so checked the flywheel and cleaned the sensor, made no difference so got a new sensor ordered. But then decided to disconnect the alternator batter cable to see if that made any difference and sure enough car fired up and was idling perfectly. After checking the voltage logs back the voltage was rather erratic not staying around 14.5v. Assuming the fluctuating voltage was throwing the timing, injectors and spark off. So a refurbed alternator was ordered (mistake), was a Bosch one so assumed it was going to be decent. Was 65 quid off eBay.

Car fired up and ran perfectly but no voltage from the alternator. This really confused me to what was going wrong now but came to the conclusion it couldn’t be anything else apart from the alternator so then ordered a brand new one from Renault Parts Direct who got it to us the next day on a Saturday. At this point we were happy to chuck some money at it to get it sorted so 190 pounds later we had the new one. Sure enough swapped the alternator for the second time and it worked perfectly. Car running well and have a voltage at a constant 14.5v. Whether the Bosch one was just a one off failure I don’t know but I wish we went straight for the new Renault one (Valero).

So now car running happily and could finally get it up to temperature get the coolant bled and check for leaks after fitting the mocal laminova oil cooler.

Last thing to do was then change the rear pads out as they didn’t have anything left on them. This was 2 full days of use at Donington, 600 miles total.

Now the car and kit is all packed up and ready for our trip to Croft on Wednesday. Looking forward to feeling the difference with the diff.