Tuesday, 30 April 2013

Back axle version 1.1

When I started the restoration of my DHC it was to provide me with a reliable TR7 to bridge the gap while working on the next and hopefully last stage of the upgrades for 't Kreng. Which automatically means that I won't start with any physical work on 't Kreng before the DHC is in proper working condition. But so far the DHC has not shown the reliability I am used to with my TR7's. Since the car came back on the road almost three years ago I had to change or repair a lot of items. As there were two leaking water-pumps, one leaking clutch master cylinder, two bad gearboxes, one worn clutch assembly, one shattered door mirror, one worn viscous coupling, one cracked fan, one broken prop shaft and of course the problems I encountered with the paint ...

As a result of all these problems with the DHC so far work on the rejuvenation of 't Kreng has been postponed for the time being. But not completely. As I had not much better to do with my spare time I decided to have another look at the digital version of the back axle set up for 't Kreng. And it was good to revive my AutoCad skills a bit! So I decided to model the axle and the necessary modifications in 3D, as this gives a much better impression on clearances etc.

Next on the to-do-list are the adaptations to the cars body, like the new upper axle mounting points, the chassis mount for the Panhard rod and the roll bar. Also looking in detail at a new rear brake set up.

And got a phone call today that the stiffening plates for the back axle are going into production soon and that the alloy sheets for the sump guards have arrived too. It looks like it's going to be a busy summer.

Monday, 29 April 2013

Getting ready for summer

... Or the last major finishing touches for the DHC (hopefully!). There have been several failed attempts over the past 5 months to work on the car, but due to illness (both mine and the workshop's owner), work commitments or just no motivation to work on the cars for various, reasons they were all postponed. But today I at last had a go at changing the clutch assembly, gearbox and prop shaft of the DHC. In preparation for the swap I brought the DHC out of its winter hibernation last Saturday, and the car behaved rather well from an engine and suspension point of view. But the overall experience was spoiled pretty thoroughly by very bad gear-changes in all but 5th gear. Especially changing down a gear after driving at constant speeds for a few minutes was very bad. Needed brute force to get out of gear and into neutral. And when it got out of a gear, it felt as if it was smashed out with a hammer. Not good, but I arrived at a friend's workshop with no problems.

Changing the clutch assembly and gearbox proved to be a pretty straight forward job. Mainly thanks to some proper tools, like a 4-post lift and a rolling hydraulic gearbox/axle stand. And inspecting the parts coming of the car didn't make me any wiser. OK one side of the clutch plate was slightly contaminated with oil but not enough for any big problems. And compared to the "new" 'box, the old one felt pretty loose, but again nothing clearly wrong with it.

So the only thing I could do was put the new 'box on the axle stand and slide it in place, which went rather smoothly. And before long only the exhaust and interior remained. And of course something had to put up a fight. This time it was (again I should say) the tubular exhaust manifold, or more specific the lower rear mounting bolt. This refused point blank to get in its allocated place. After a rather frustrating hour or so I manoeuvred the manifold out of the engine bay to check the threads. Needless to say the bolt slipped in without any problems, and the thread was fine. But it turned out that the thread insert I fitted a few years to the upper rear bolt had somehow got dislodge a bit and as a result it got damaged. With the insert removed we tried again, but the result was the same.
And although the bolts all looked undamaged, in the end the problem was solved with new bolts. After which refitting the rest of the exhaust and the interior took just over 15 minutes ...

As it was well past 5 o'clock by now it was time to pack my gear and head for home. And needless to say it was with some anticipation that I started the engine and drove out of the workshop. Well all the gears are working, and although in the beginning it was a bit notchier compared with a good LT77 'box, after a few miles the gear changes became progressively better, result! Also the clutch feels much better compared to the old one (maybe not so surprising as the old assembly was almost twenty years old), and the car has become much quieter. The only problem so far is that the new 'box has a bit of a rattle with the engine idling and 'box in neutral. But I have to confess that the engine needs a tune up as it idles @ ±500 rpm at the moment (if you can call that idling)

oh ... and I forgot my camera ...