Rear Axle - Jag Rear overhaul Part 1

One of the jobs I need to be getting on to is the Jag Rear overhaul. I want to have a few of the components chromed and I will use the RPMS prize money I won to do this.

Over the past year I have collected up a few parts....the jag rear that is in the chassis, another one similar so I have spare axles and wishbones, 2 x powerloc limited slip centres and 2 x sets of 47/11 gears (4.27:1).

The powerloc limited slip centres are a unit that goes in the diff and give traction to both wheels. If one wheel starts to spin the clutches inside the diff grab and some of the power gets transferred to the other wheel that has traction, so you get power to both wheels. This means the car gets "drive" and stops skidding.

The gear sets I have will allow me to have the engine and trans turning over at the same revs that they would have at the same road speeds in the original car they came from. I figure Mr Toyota spent millions of dollars refining the engine, trans and computer etc to perform optimally, so if I can replicate that, I should be able to reap the benefit of all that refinement.

In effect then what I have is a whole lot of buckets of bits.

The bucket in the next picture has the powerloc centres and spare sets of gears in it. One of the powerlocs is the unit to the top left of the photo below. It has spiral looking teeth around its edge.

To the right of the photo is one of the sets of gears I want to use. They are currently mounted on a non-powerloc centre or what is known as "open diff". You can see the difference if you look closely. The powerloc is like a solid centre (with clutches inside) whereas the open diff on the right, you can see in the centre of the unit there are some smaller cogs. These are what is known as the "spider gears".

Then I have the diff head thats out of the chassis....

.....and a spare one.

I threw all this into the car and took it all down to Diffs R Us in Otahuhu to talk to Lee Marriner and get his views on which head to use and whether or not I had enough other bits to get a complete unit out of. The verdict was good and I can choose either diff head as they are both suitable casings to use.

In the end I have decided to go with the one that was in the chassis as the mount points for the brake calipers looks like it will be the easiest to work with. That will be the next blog on this topic but in the meantime I have added a couple of videos showing how a diff works and also whats inside a Powerloc diff centre.

This first video explains how an open diff works.

This next video shows the internals of a unit that is very similar to the Powerloc centre from a Jag. You will get to see the clutches I was talking about earlier. Unfortunately I haven't been able to find a video to show how it all works, but in effect the clutches you see in this video "grab" and provide drive to the wheel with traction, rather than letting all the power go out to the wheel with no traction. Hope that makes sense. Other than that the workings aren't too dissimilar to the one in the above video.

Thats it for now, but I will send a few more blogs as I rebuild the Jag rear. Stayed tuned!

Article - NZ Rodder Magazine

No I haven't fallen off the face of the earth, but I guess you could be forgiven for thinking that as it has been 2 1/2 months since my last post.

This is all because we have moved house and the time taken to find another place, pack up the old one, move to the new one and get it sorted all takes it toll on everyday life and the Coupe has had to take a backseat for a while. No that can't be right, Coupe's don't have a backseat.

Anyway, I haven't exactly been sitting there doing nothing. I have had about 5 things on the go which will see over the next few weeks as I finish each one and publish a blog about it.

One of the biggest things taking place is all because of the fact we moved house actually. You see the garage at the new house is 2 metres longer (albeit 1 metre narrower) which means I have room for a bodyshell. It will be tight, but it should fit, just! It was ordered a week or so ago and it will time in with the Kumeu Rod & Custom Show which is held locally, late in January. This means the guy making it gets a bit of warning, can bring it up from Taranaki with him when he comes to Kumeu and can use it as a display on his stand all weekend. I can then bring it home at the end of the weekend. A masterplan!

Another major event was a feature article of the project in NZ Rodders September issue.

Here are a couple of pics of the spread. It was covered by Debbie Jarvis. Debbie was the one who wrote article for my last Hot Rod a couple of years ago, and she is keen to do a series of in progress articles as this car is built. I thought there wasn't much to see really but Debbie did a great job with it I thought. See what you reckon. Remember you can click on the pictures to see a larger version.

Keep watching there are plenty of things happening!