Tag Archives: rear axle

Rear Wheel Bearing Replacement

2400 miles driven and one of the two rear axle wheel bearings has failed on a sub 2500lb car.  Sad shape of affairs this is indeed.

Fist off, the wheel bearing in question has the SKF name all over it; made in of all places, China.  I have a problem with offshoring and a bigger problem when the offshored goods are defective.  QA was definitely not in the picture when this bearing was made.  And no, this is not the first one to fail.  My cousin Jim Thompson’s TR4 had the exact same thing happen on an identical rear axle as used on bowtie6.

So what is all this fuss about?  Let me show you.  After lifting the rear of my TR6 up in the air, we were able to determine the driver’s side axle bearing was at fault.  I took the caliper off, then the rotor and the retainer plate off the rear housing.  A couple of strikes with a deadblow hammer and the axle was out.  This is what it looks like:

The picture above shows the bearing and on top of it the retaining ring.  In order to minimize damage to the axle, the bearing is cut as follows:

And once the outside race “pops” (it is under tension and cutting the outside race eventually makes a muffled “pop”), we get a chance to see inside.  This is where things get very interesting:

In the picture above we have the outside race cut showing the ball bearing retainer.  It is what lies below the ball bearings what is of interest!

Here we start to see the root cause of the problem.  The inside race should be slick, polished and accurately ground.  Look at the photo above: the lower half is indeed properly hardened and finished.  However, see the top half?  It looks very rough indeed.  That is where the racket was coming from.  Another couple of pictures:

And…

Further inspection revealed the outside race was in good shape.  No case-hardening issues there.  However, the inner race was very poorly made – somehow the case-hardening process was not properly applied and the surface of the inside race pitted severely after only 2400 miles.  This cannot be blamed on poor lubrication because these are sealed bearings.

A new bearing has been sourced – unfortunately it is SKF.  I just hope I’m not here in another 2500 miles talking about another bad apple.  Here is a photo of the new bearing being pressed in:

Once I got the axle back in the housing and bolted it all back together we were set to go.  I put about 50 miles this afternoon and all is good.  I just keep my fingers crossed the new bearing lasts a little longer.

 

2,400 Miles and Counting…

I’ve been able to rack up about 2,400 miles on bowtie6 so far.  And, it has been a blast!!  The frame is rock solid, and with the ECM tweaks the engine is so much more responsive.  Yet we have been able to see 28mpg in city driving no less.  Not too bad considering the tune is now more so towards performance rather than for economy and I’ve been really putting my foot into the electronic throttle pedal.

A few weeks ago, I found a vendor that makes an awesome coilpack cover for the Ecotec.  You can see this in the above picture.  Four screws with spacers hold the water-jet cut aluminium cover and very nicely hides the valley between the cams.  Looks trick.  I was thinking about unbolting the intake, cover and valve cover and perhaps having this all crinkle coated in black.  Maybe later this year…

Along with the great news, there has been on unpleasant development:  a bad wheel bearing on the new rear axle.  It seems like we got hold of a crappy “foreign” made wheel bearing and it started making a racket last week.  New ones have been sourced and I’ll be taking apart the axles this weekend.  All good – the diff fluid needed to be changed after “break in” so this should be a fun Saturday.

I’ll have pictures and a full report once we get the new bearings installed.

Final Pics of the New TR6 Frame

Here is a final set of pictures of the new frame serving as bowtie6’s backbone.  The body has now been permanently bolted on, so this is the last set…

Some misconceptions have surfaced as to the origin of this frame.  Suffice to say this is NOT (repeat, IT IS NOT) a RATCO frame.  Those folks produce a nice aftermarket frame but this one is all bespoke and designed for the ECOTEC and the solid rear axle specifically.

Why so many entries on this blog about the frame?  Well, simply put:  I am very proud of it.  My cousin Jim Thompson has put together a very clever, lightweight and strong frame using modern frame-building techniques and materials while being able to retain some of the original TR6 bits.

The front suspension is almost all stock TR6.  The “A” arms, ball joins, steering rack, sway bar, trunions, hubs and rotors are all stock Triumph.  The calipers are Wilwood.  The springs/shocks have been replaced with coilovers.  The coilovers offer several advantages:  no spring compressors, spring interchangeability and the ability to control ride height.  However, they are not cheap but worth every penny.

The rear is all new and it is trick!  The axle is an 8” Ford, custom sized.  It was cut on both sides and custom cut axles have been sourced from Moser.  The gears are from Motive; posi-traction (of course) with a 3.80 to 1 ratio.  Disc rotors and calipers are used on the rear end (with full emergency brake capability using the original TR6 cables and lever), as well as matching coilovers.  There is a four point suspension holding the axle in place with Heim ends on all four control arms.  We tried polyurethane ends, but they did not survive the power from the ECOTEC.  Enter the Heim ends.  Again, only the best have been purchased.  These are precision ground steel (normally used on sprint cars) along with special boots to keep debris out.  Brake and fuel lines are all hand made, hand fitted and hand formed from stainless tubing; with teflon lined, braided lines going to all four calipers.  Again, only the best has been sourced.

This is the second frame built using this design.  The first frame is under Jim’s TR4 and it has proven to be astounding.  It is very stiff – gone is the ‘flex’ that the original frame exhibits.  The new frame is made from much stronger square tubing.  This tubing is a solid square, not a “U” channel with a cap spot-welded as in the original design from Triumph.  I repeat, this is very strong stuff.

Finally, the ECOTEC 2.4 litre engine sits on special plates (on the frame side) that allow the use of the original Solstice engine mounts as well as tranny mount.  The mounts are really nice because they are made with rubber to help isolate vibrations.  Furthermore, the GM mounts have a locking mechanism that if the rubber ever fails the engine will only rock a very small distance and the locks keep it from making undesirable and expensive damage.

Finally some thoughts:

  • I realize this frame has nothing in common with the ‘original’ frame.  My condolence to the purists – but the idea is performance and this frame works and works very well.
  • I’ve read where folks discuss the shortcomings of the AISIN gearbox and say the gearing is all wrong.  Depends what you want to do:  bowtie6 is not built as a drag car.  Yes, first gear is a bit tall and that might not sit well with folks.  I don’t mind it.  From the experience gained from my prior setup and my cousin’s TR4, the car excels like a dream in second, third and fourth.  These three gears are quite simply awesome.  What about fifth?  Well, suffice to say that at speed and in fifth gear all you have to do is punch it and the car will take off.
  • The last thing about the new frame has come as a bit of a surprise to me.  In my cousin’s TR4 the steering “effort” has been reduced significantly.  The “far-back” engine placement has something to do with this.  But there is also the extra pressure of the original spring pushing on the “A” arms that has been deleted.  The new “feel” is much more positive, lightning-quick and a delight to use at parking-lot-speeds.

Here is the final picture gallery of the frame prior to the body being permanently installed.

 

bowtie6′s New Differential and Rear Suspension

bowtie6′s new frame gets a new differential.  In order to handle the power of the ECOTEC – remember boost is in the plans – we needed something that would not break.  Furthermore, one of my requirements for the new drivetrain is to have full posi-traction (and by this I mean the real deal and not viscous).

In the following gallery, you will see the following:

  • The rear axle is a narrowed 8″ Ford.  Yes, it might be a little overkill but again, this is all being built so we don’t have any unexpected “failures”.  The solid axle in this application will by far surpass the IRS as originally implemented.
  • The diff is a Motive full posi-traction unit.  It is set up with a 3.80 to 1 ratio – it is a bit tall in first gear with the Solstice’s AISIN gearbox but you have to remember this:  I am not building this to be a drag car.  With this ratio, the car is extremely quick and nimble at speed.  From the setup in my cousin Jim’s TR4, we have determined this rear axle ratio works fantastic with the engine in second, third and fourth gear; with fifth being even more fun at speed.
  • You can see in the pictures the special order Moser axles.  These were custom made with the correct length in order to handle the narrowed housing.
  • The rear axle is held in place as a four point suspension.  The control arms are fitted the special Heim ends.  These were quite pricey and come with special seals to keep dust and grit out.  Why Heim ends?  I’ll have an article about this later…
  • Finally, take a close look at the driver’s side axle:  the rear brake rotor is fitted.  Yes, we will be re-using the disc brakes we had previously used.
  • Not shown in the pictures is the all new, custom made brake lines.  We are using stainless tubing this time and it has all been hand made, and bent just special for this frame.  I’ll have a future article about this because the mounts that Jim made are real special.