Finally!

[Andy]

Had another bash at this during lunch time, I'm not about to remove the pinion just yet, I'll wait until the new outer bearing turns up so I can get the sliding fit all spot on.

What I did achieve though was an increase on the backlash from .006" up to .009" this gave me following pattern...

Drive:


Coast:


The coast pattern is pretty much spot on for what I want to achieve, but the drive side is just a tad too far out for my liking. I'm going to leave the carrier shims where they are and replace the pinion shim. This should hopefully bring the drive pattern is, which at the same time bring down the backlash figure.

[Cunning Plan]

Interesting part of the project. This is part of drive-train build process I did not know about, so it is interesting to read.

(P.S. Have you seen the latest HotRod garage? They are playing with gear boxes )

[Andy]

I had a long list of things I wanted to get done over winter for next years RWYB challenge and the Power Tour. In the end I spent far too much time messing around with the engine, which I really don't intend on fitting till summer at the earliest, than getting on with the jobs I really wanted to do.

So along with the differential bits I bought, I've also purchased adjustable Panhard bar, adjustable Lower Control arms, uprated Torque arm, Lakewood drag shocks, KYB adjustable front shocks and a set of lowering springs. The springs were more an appearance thing than anything else. I've had far too many comments about my arch gap...

Most of the bits I've bought all bolt onto, or around the axle, so going with a complete refurb on the whole shooting match seemed like a plan. Once I have all the above bolted back in again, I shall then be taking it over to a friends workshop to have the SFC welded in.

[Ralph]

win win win. Always wondered where this thread was and then stumbled across it in somewhere I was not expecting!

Awesome stuff though chap.

I refuse to offer any more help in your workshop until that kettle can actually be plugged in and the remaining tea making facilities are in place haha

[art b]

lots of interesting stuff and good work andy

[art b]

Quoting: Ralph

I refuse to offer any more help in your workshop until that kettle can actually be plugged in and the remaining tea making facilities are in place haha

and i thought andy was a nice bloke until this ....

[Ralph]

It was all a vicious lie to get us there.

Asked if we wanted a cup of tea, I volunteered to fill the kettle... Told not to use the water from the tank/there isn't any... So I go in armed with my bottle of water I happened to have with me... Only to find out there is no base for the kettle, cups, tea bags... Well anything else.

Wasn't impressed. I'd rather have been told there was nothing form the start then expectations would not have been raised.

Such a shame.

There have been new bribes recently so I may well give him a 2nd chance.. If this is also another 'wolf crying' incident it may well be the last time haha

[Roadkill]

Quoting: Ralph

I'd rather have been told there was nothing form the start then expectations would not have been raised.

I assume the issue was immediately rectified by way of a take-away pizza / curry / chinese ?



*** Sudden flash back to when we were working on Incursus' Duster at my works unit at silly-O'Clock at night one time and Art knocked on the door with a KFC in hand !

That was awesome.  

EDIT - back around then : http://www.mkb.cc/forum/index.php?action=vthread&forum=2&topic=335&page=1\" target=\"_blank\" rel=\"nofollow\">http://www.mkb.cc/forum/index.php?action=vthread&forum=2&topic=335&page=1

I only paint Black.  

[art b]

Quoting: Roadkill

*** Sudden flash back to when we were working on Incursus' Duster at my works unit at silly-O'Clock at night one time and Art knocked on the door with a KFC in hand !

 ya gotta keep the team happy ..

it may have been when we were working on your maro too
or was pot noodles...

[Andy]

Bit of an update, new bearing arrived, I had suspected the outside pinion bearing and race of being shot from the initial uninstall and fighting against it to remove it. Rather than risk anything though I decided to change both bearings and races, this does mean that any patterns from before won't be the same as the inner pinion bearing will also change the depth that the gear is in the case.

Just to give an idea in case people are scratching their heads about how this all works...

Pinion Preload

Whenever checking the pinion depth or backlash or even running a gear contact pattern, the first thing to ensure is that the pinion gear is actually under a load and not 'free spinning' in the bearings. This is to replicate the effect that the crush sleeve will have on the bearings on the final install. As the crush sleeve is a once only use item, it isn't used until the final install once all the other items are checked over.



The preload is determined by how tight the pinion nut is and how much pressure the yoke is forcing on the back of the outer pinion bearing. The preload is measured in INCH pounds and it is the rotational force not the initial break away force required to make the pinion rotate.

On the final assembly of the axle, this preload needs to be achieved but with the crush sleeve used between the outer bearing and a location on the pinion gear shaft. The crush sleeve ensures that there is always a preload there and that there can't be any movement towards the ring gear of the pinion gear, unless the nut comes off.



Pinion Depth

The pinion has to angular opposed bearings on it, one main big one called the inner (sits right behind the pinion gear) and has the depth controlling shim between it and the back of the gear. The outer is at the opposite end and it pressed on from behind by the yoke.



The depth control is important to the gear setup, as too deep engagement (thicker pinion shim being used) risks the possibility of the gears binding under extreme load. Too higher a contact (thinner or no shim being used) risks tooth breakage from the load being focused on the edge of the tooth.

Backlash

Backlash is the physical movement between the pinion and ring gear. This is controlled both by the pinion depth shim but largely also by the carrier preload shims either side of the carrier between the casing and carrier bearings.



These shims adjust the location of the carrier in the casing, moving it towards the pinion (adding shims to the ring side and removing them from the other side) decreasing backlash and increases the engagement. Moving the ring away (removing shims on the ring side and adding on the other) will increase the backlash seen between the ring and pinion.

Whenever removing shims from one side, you must add the same number to the other. This maintains the carrier preload on the bearings. For all these test installs the carrier has been a 'snug fit' in the casing. When it comes to the final install and the shims are installed for good, it is always a good idea to have it tight as possible, with the last shims being tapped in with a brass hammer.



Checking the backlash is done with a Dial Test Indicator on the outer most edge of a tooth, while holding the pinion gear and rocking the ring back and forth.

Gear Contact Patterns

So once you have done all of the above it is now time to finally mark up about 4 - 5 teeth on the ring gear with the yellow gear marking compound. This stuff is great for being able to see what contact the gears are actually having when then mesh. From the patterns you can get an idea of what adjustments to your setup are required.

It is crucial to have a decent or acceptable pattern, as there will be no fun when the first time you hit it and the ring gear teeth say adios, this is the most time consuming, but also rewarding stage of the build, as you actually get to see what all the stages above achieve. The hardest part is understanding what changes to the above (Pinion Depth, Backlash) will do the contact pattern you see.



The diagram above is a good way to understand it, but they are very much 'in a perfect world' adjustments. As I found with mine, I had the drive side move all over the shop while the coast pattern seemed to say pretty centralised. This can throw you off when it comes to adjusting the next gear run.

This video however explains it a lot better than diagrams like that.

[Andy]

I set aside 4 hours yesterday to get the install wrapped up.... I wasn't intending on rushing it at all, and I didn't BUT holy crap!

First thing was to get the backlash up a tad. As read in the motive gear manual .007" - .009" was recommended. I managed to get it spot on .007" which was great, as well as that, I've now preloaded the carrier to the point that I have to use a bit of brass bar and tap in the last bit of shim on the non-ring gear side. Very confident it's sat in there nice.

So stripped it all out, blew out the case completely with the air gun, cleaned the races down and smeared some gear oil on them. Cleaned most of the gear marking compound off, found it very difficult to remove all of it, and was more worried about putting it all over the bearings. I'm sure it won't cause any damage, but would prefer there wasn't any contaminants in there.

Installed the pinion seal nice and secure with the outer bearing in place. Oiled up the big pinion bearing, installed the crush sleeve, put a bit of oil on the shaft where the out race runs on. Installed and put the yoke (now with rtv on the splines of the yoke) drew it up with the old nut and washer. With about 1/4" of travel left on the outer pinion bearing I put the new nut on with loctite on.

I will say now, up until this point everything was going great... trouble first started when I put the new pinion nut on. Jesus Rollerskating Christ, that's tough just putting it on! This one from Richmond was obvious crimped in three place around the end. As soon as you hit that it becomes INCREDIBLY tough to put on there. However with two breaker bars, plus a 4' extension on each bar I finally drew the nut up tight so there was no more play. Now to get the crush sleeve crushed. In comparison, that was easy, and slight tug got me to 10" Lbs, then a tiny and I mean TINY, budge, got me to 18" Lbs. I'm not a gambling man, but in this game of black jack I went twist and boom, straight on 20" Lbs, with another TINY budge.

This whole sorry story of just trying to get the nut down though took up far too much time and I had to call it quits as I was off out for the evening. So I ended up going back today to finish it off.

Jobs to do were to install the carrier, recheck the backlash and adjust accordingly. Reinstall the axle bearings, seals, drum backing plates with my new anchor pin bolts, half shafts, c-clips, install the spacer, locking cap on the diff brake lines, and all the other fixings.

Ended up taking a good few hours to finish it. Only thing that miffed me was the cover. I had bought an aftermarket aluminium cover that has the ability to put pressure on the carrier caps. Only problem was that the bolts were short by about 1/2" They only got about two turns of thread out of them. Very disappointing after all the effort I've put into it.

Either way, here's the final item, weighs a fair bit more than it did removed. The LSD, Gears and Half shafts are much larger than stock or before.

[Ralph]

I am looking forward to this going back in!

:D

Gonna be snaking all over the place!

[Andy]

[Incursus]

[Titsy]

[Andy]

Spent a couple of hours tonight mock fitting the other components going on the axle for the install on Sunday.

The lower control arm relocation brackets were great fun trying to fit over the freshly painted axle case. Nothing a hammer couldn't solve though.



Below you can see the adjustable Lower Control arms, need to get a smaller grease gun as mine is too big for the nipples on the arms.



As always with these things I spent about an hour just trying to take two bolts off and fit the new poly torque arm bush in the back of the transmission.

[Andy]

With the help of Ralph and Adam, this happened yesterday...

















Now just need to break in the new gears and give her a good wash and wax!

[ianjpage]

looking good now it back together again

[Ralph]

It was a day of much victory!

Can't wait to see it scream down the track with it's new rear end!

NOW GET THAT ******* MOTOR BUILT!!!

[Andy]

I guess it's time for the Bi-annual update!

So, since the rear end went in and all the suspension work, it has now been a case of seeing what improvements it has actually made to the car on the strip. The whole purpose of the exercise was to try and make the thing more consistent and make it a bit more predictable for Sportsman ET racing.

After a couple of good RWYB sessions the car was now settling down to show that the new rear end had picked up a good couple of tenths over the 1/4 and that it now was far more consistent than it ever had been. No longer was I wheel spinning one off the line, but instead it now chirps going into 2nd and 3rd.



Now with the car performing better than it ever had I decided it was time to actually enter into a competition, thanks to my mate Tom the Camaro has now been dubbed 50 Shades of Green Racing, which kinda works! Anyway, first event was the Springspeed Nationals at Shakespeare County Raceway. Having done the Dial-in day before I was used to the format, but doing it for real in competition adds a whole new level to it.

I qualified poorly and couldn't figure out where the track was going. I massively over estimated the difference in tracks between Shakey and the Pod which left me second guessing what the car was going to run. In the end I qualified second from bottom, taking on the runner up in the Sportsman ET championship in Round 1. Thinking that that's where my weekend was going to end, it was actually quite good fun running him down by half track and then just tapping the throttle to stay ahead of him through the traps! In round 2 I ended up with Number 1 qualifier Jon Crawford, running his VW Sharron. Again I ended up running him down by 1000ft and just keeping myself ahead as we crossed the finish line and winning. That put me in the Semi-finals against Ricky Hale who now was going to be running me down. This is where I struggled as by now the track had come round and out of no where, instead of running 16.2, I broke out and set a new track PB of 15.9 - I thought what the hell, still a PB!

So now with that under my belt, I've decided to enter Sportsman ET at the Summer Nationals next weekend at Santa Pod. Should be a good weekend and an interesting one!

That said, I've still been doing work on the car, I bought a set of 4th Gen seats, as I wasn't overly happy with the way the 3rd gen ones just flop forward, there is no locking mechanism except for when the car decelerates, then the seat locks up.



I also had fitted last weekend the Alston subframe connectors I bought years and years ago!



I was really skeptical about these, expecting them to not really do much, probably just add extra weight that I had been trying so hard to lose, but my god, the difference really is night and day. The dash no longer rattles, the doors don't rattle or bounce around when driving, the car feels so much tighter and the rear end really feels like it digs in through corners. I got them welded in by Wolfy and Wolfy's Workshop just outside Brackley. Managed to score some ramp time on Tom's 4 post lift which meant all the suspension was preloaded while they were welded in.

[Ralph]

Have you got any more under car shots? Be nice to see it with all your new trinkets.

[FUBAR]

my god, the difference really is night and day. The dash no longer rattles, the doors don't rattle or bounce around when driving, the car feels so much tighter and the rear end really feels like it digs in through corners.

I really should do this, I said to Rocky when I bought the IROC from his uncle that i'd be back later in the year to have SFCs fitted... that was 9 years ago!!

I also REALLY should fit all the Spohn stuff i've had for nearly 5 years for the rear end of the car, paint the rear axle and fit the TA performance diff cover i've also had for the same length of time!!  I have 2 weeks off in late September... that would be an ideal time to fit everything and get the drive shaft balancing checked and the tail seal changed on the 700R4.

I'd like to fit these too...
http://www.spohn.net/shop/1982-1992-GM-F-Body/Suspension/Springs-Accessories/Eibach-Pro-Performance-Lowering-Springs.html
But am really nervous about "taking the Plunge" + it'd then be classed as a "Modified Vehicle" for insurance

Sorry  :hijack4:

[Andy]

Up until now I though the tyres and wheels were the best thing I'd done to the car. Changing from BF Goodrich on 15s to Kuhmos on 16" rims made the car a completely different driving experience. Add to that the KYB adjustable shocks and new Lakewoods in the back as well as the Summit lowering springs, the car really does handle very well, the SFCs were just the icing on the cake, making it feel much like a modern car and one you can throw around comfortably!

If Rocky hasn't got time to make you some, get some of the Alston ones, they're not as intrusive to the underside of your car, but thoroughly recommend lifting the passenger and drivers carpets and underlays if you get them welded in.

Regarding insurance, while technically it's a mod, I see it more as a replacement of like for like, but better. The only physical mods being the SFCs, which I'd love to see how an insurance person would warrant as a modification.

Still in awe at how many sqeaks and rattles have been sorted though!

[Roadkill]

it'd then be classed as a "Modified Vehicle" for insurance

The list of modifications for my Camaro went into three pages !!!  Total additional cost of mods = £0.

Insurance was £200 this year, based on 1500 miles p/a.

I really wouldn't worry.

In fact I'd worry more about doing it and NOT disclosing it 'cos they won't pay-up for sure in a claim.

[Jamieg285]

it'd then be classed as a "Modified Vehicle" for insurance

The list of modifications for my Camaro went into three pages !!!  Total additional cost of mods = £0.

Insurance was £200 this year, based on 1500 miles p/a.

I really wouldn't worry.

In fact I'd worry more about doing it and NOT disclosing it 'cos they won't pay-up for sure in a claim.

Who do you insure with?  I'm due for renewal this week.