Back together

Halfshaft is now back in the car. Everything is bolted into place, flexible brake pipe, and handbrake cable back in place, brake adjusted.

Tomorrows job will be bleeding the brakes then hopefully the GT6 will be ready for an MOT re-test at last....

All back in

Halfshaft rebuilt and going back on the car

I finished assembling the halfshaft tonight, fitting the brake shoe assembly and hub, bolting the inner halfshaft to the rotoflex coupling. Once the coupling was bolted up it was time to cut off the steel compression band that comes fitted to new rotoflex couplings.

I then did a bit of preventative maintenance to safe hassle later on. The long lower outer wishbone bolt has a tendency to seize up on rotoflex suspension. When I replaced the bolt and wishbone trunnion bush  assembly a few years ago I used copperease grease to try and make the job easier. This has worked as the bolt still turns and can be pushed out reasonable easily, so I took the opportunity to re-grease with copper ease. The nylon bushes still have no play so I haven't replaced them this time around.

Then it was time to get the halfshaft back on the car. I wriggled it into place and replaced the diff UJ flange bolts to hold the shaft in place. Then played about with jacks and prybars to get the lower inner wishbone bush into place on the chassis bracket and got the bolt in place.

Copperease added to the lower outer wishbone trunnion bolt hole

Cutting the Temporary Rotoflex Compression strip fitted to a new coupling

The next job ids the toughest one on rotoflex suspension cars, replacing the upper vertical link swing eye bolt. The essential tool here is the famous Triumph spring lifting tool. It was getting late so I've set everything up ready but will leave it until the weekend to get the jacks and prybars etc out to get this into place. Always a job that requires plenty of cursing and swearing!

The Rotoflex Springf Lifting Tool in use

Getting Ready for replacing the upper vertical link spring eye bolt, the toughest job when replacing a Rotoflex halfshaft

Coming back together now

I feel like I’m starting to make progress at last

I went up to the Triumph Spares Show at Stoneleigh where I had arranged to meet Tim Ward who kindly donated a couple of unknown quality Rotoflex hubs. I checked them out quickly at Stoneleigh and one looked like it would be OK the other had some wear on the inside face. Richard Brake had also collected some 5/8 unf nuts, they were supposed to be the thin type like the original fitment but they are still thick like the ones all the Triumph Suppliers are providing, however it doesn’t do any harm to have spares…

Once Home I cleaned up the two hubs that Tim had given me, one was definitely too worn and also had a big burr  due to previous big hammer abuse that would have stopped the drum sitting flush without some major filing but the other one looked good, the splines inner face and bearing faces in good condition and I checked the flange for run out and it was true. The only issue was that the two holes for the brake drum screws both had screw shafts stuck in them with a slight counter sink which looked like someone had probably drilled the heads off the screws to get a brake drum off!

Anyway, a bit of work carefully drilling them out with a pillar drill and re-tapping the threads had them sorted. So I now had one decent hub. I then changed over the wheel studs pressing in the new extended ones.

The rest of yesterday evening and this evening was spent assembling the drive shaft assembly to check spacers and shim requirements, building up with dry bearings to check end float and then packing with grease, reassembling and finally torqueing up the driveshaft nut with a new nut and Loctite threadlock.  I also re-checked the hub for run out on the final assembly  and it’s fine. I’ve now run out of time and I only have a couple of hours on Thursday night available to work on the car this week which should give me a chance to a chance to build up the brake assembly and bolt on the inner drive shaft  but it will be the weekend before I can start putting the shaft back in the car.

Plenty of grease used to pack the bearings



Replacement hub Torqued down with new nut on driveshaft locked iwth locktite threadklock and new Extended length wheel studs fitted.

 

Dodgy Flange Piece Oooh Errrh

I got the halfshaft assembly all built up with the brake shoe assembly and drum last night. Gave the assembly a spin to ensure the brakes weren’t binding and noticed there was a severe amount of lateral run out on the drum face where the road wheel would sit.


I checked it with my DTI gauge and the run out measured in at well over 2mm at a radius of 55mm. I calculated that it would have equated to a 12mm run out at the wheel rim, obviously not acceptable!

Measuring the Lateral Run Out with a Dail Gauge

I suspected that the most likely thing wrong would be a bent outer halfshaft although it could also be a bent hub. To be honest it was getting late and I was frustrated and I thought damn it lets just get a complete 2nd hand halfshaft assembly to bolt back in the car. Sent off various emails and a post on the Club Triumph forum after midnight last night to see if anyone had any for sale. Lots of responses from the Forum and one from a Wins International who were listing 2nd Hand halfshaft assemblies on their web site. Plenty of responses but having thought about it I have a new bearing, a new rotoflex coupling a vertical link with good lower wishbone bushes and a long bolt that’s not seized so it would be daft to go over to a complete unknown quantity assembly when most of mine is good. I therefore decided to strip out the hub and outer halfshaft and inspect carefully to find which parts are damaged.

The most obvious culprit, the halfshaft actually seems to be true, but the hub certainly isn’t. I put the back face of the hub the a flat surface block of my Vice and measured the distance to the front of the hub flange around the circumference with my digital callipers. Sure enough the hub is distorted, the largest and smallest flange distance dimensions differ by 2.6mm around the circumference!

Measuring the Hub Flange Distortion with digital Calipers

New hub required then. Post put on the Club Triumph Forum to see if anyone has any good 2nd hand rotoflex hubs, I’ll probably ravel up to the Triumph Spares Show at Stoneleigh on Sunday to either pick one up from a member or try and find one. Failing that Canley Classics do have new ones but they are about 80 quid, ouch!

The other pain is that I’ve fitted my new outer wheel bearing and extended wheel studs to the bent hub so I’ll have to carefully try and recover these.

Good Job I had a stock of spare outer halfshafts!

The work to replace the wheel bearing and rebuild the halfshaft continued tonight. I had a bit of advice from two well respected Triumph aficionados who suggested that it was better to have a bit of pre-load on the bearing and to leave well alone now I had come up with zero end float. However, the fact that the larger distance piece and 5 thou spacer arrived in the post today I thought I’d give setting up another go. Probably just as well as I ended up adding another 6 thou of adjustment to get 1 thou of end float measured and verified with my DTI gauge. I would have had 5 thou of preload if I’d left the setting alone which I think would have been too much so I’m happy with the end float now.

Bearings were then greased, oil seal added and everything assembled with the replacement half shaft I’d selected from my “good” 2nd hand spares. Except it turned out not to be a good half shaft after all, despite the fact that I drifted the assembly fully together first to save too much drawing the bearing down with the shaft and the thread on the shaft looked good it stripped before I got to the required tightening torque.

Damn It!

I then had to strip out the shaft, remove the big block spacer, dust cover disc and rotoflex coupling and build up another shaft. I picked what I considered to be the next best shaft, it looked good except there was a slight taper on the last few threads which is why I had demoted it to 2nd place. However on reassembly I torqued down the halfshaft nut to the top end of the 90-120 lb/ft setting, I used loctite thread lock, even more essential with the tapering of the end of the treads making the nyloc of the nut pretty much useless on the thicker than standard nuts that seem to be the only ones you can get hold of nowadays.

Essential addition, Loctite Threadlock due to the thicker than original halfshaft nuts now supplied by Triumph Specialists.

Torque wrench is essential to ensure the right Torque as it's bloody tight, 90 - 120 ft/lb

I was hoping to get everything ready for refitting the halfshaft to the car tomorrow night but the replacement of the stripped halfshaft lost me quite a bit of time. I’ll reassemble the inner halfshaft to the rotoflex tomorrow, build up the brake shoe assembly and replace the hub tomorrow night and start refitting the halfshaft on Thursday night. Hopefully everything will be fully back together overt the weekend and I can re-submit it for MOT next week. Unfortunately this will be past the 10 working day re-test limit and with the new computerised MOT system it will have to be a full test rather than a re-test. The MOT will also have run out by then so no legal way to road test the car until I’m on my way to the test station although I’ll no doubt run it around the block carefully before then.

Slow Progress when you have to wait for parts through the post

Carrying on with the halfshaft rebuild but it’s a slow job when you have to wait for parts to arrive via mail order. Especially when you can’t order them all in one go. With the rear wheel bearing adjusted by a distance spacer and shims it’s not possible to work out if you need different spacer and shim combination until you get the unit assembled with the new bearing.


Anyway, I have got to the stage now where I’ve been able to determine that I need to order a different size spacer and shim combination. I drifted the new bearing races into place in the vertical link and assembled with the hub and bearing in a dry condition (ie no grease) to measure up. Using the one spare distance spacer I had plus two 3 thou shims I used the Canley Classics method of measuring using a straight edge across the bearing/inner shaft face using feeler gauges. It seemed that I would have an end float of 2 thou which is within the ½ thou to 2 ½ thou tolerance recommended by Triumph.

New Bearing Races Drifted into Place in the Vertical Link

Measuring the predicted end float using the Canly Classics Straight edge and Feeler Gauge Method

I then assembled with an outer halfshaft to check the end float with a DTI gauge. I used an old outer halfshaft and nut as the thread is a weak point and I didn’t want to risk damaging the replacement halfshaft with the unnecessary assembling and de-assembling. I drifted the assembly together to get a good portion of thread showing and then tightened up the axle nut to 110 ft lb which is towards the top end of the torque setting which draws the hub assembly onto the halfshaft fully home. Although the bearing was rotating freely I couldn’t detect any end float which was also borne out by the DTI gauge. I therefore reckon the distance spacer and shim assembly I have used is set with pretty much zero end float.

Checking the Bearing End Float with a DTI Gauge

I’ve currently used a 144 thou spacer and two 3 thou shims. I’ve ordered the next spacer size up, 148 thou and a 5 thou shim from Canleys. Although the 5 thou shim isn’t shown as part of the hub assembly in the parts manual it is available as a pinion shim part of the diff assembly. With the two spacers and 3 shims I should be able to come up with various combinations in 1 thou increments until I get the correct end float which will be verified with my DTI gauge. I’ll then assemble together with the replacement halfshaft and a new nyloc nut. 1 pain is that it seems non of the traders supply the correct nut any more, the original nyloc was a thinner than standard 5/8 UNF nut, but the last two suppliers I’ve used when doing halfshaft rebuilds have only been able to supply a full thickness nut which means there is very little shaft for the nylon locking to engage with. I’ll therefore use loctite threadlock on the assembly just to make sure.

Another job I’m doing at the same time is replacing the weel studs with extended versions and fitting 10mm wheel spacers to get around a clearance problem with the Cosmic Alloys potentially fouling on the shroud of the lower wishbone bush. I ordered a par of spacers on ebay that were supposed to fit wheel PCDs of 95 – 114mm. Triumphs have a 95mm PCD so these should have fitted. However although they go over the studs they won’t sit flush and fouled on the lower portion of the stud. I’ve measured the wheel spacers carefully and it seems they have actually been made with slots to suit a 100mm minimum PCD rather than 95mm. Despite the bubble packing stating 95mm! So trying to get a refund through ebay at the moment. I’ve already fitted two of the extended wheel studs so as a temporary measure I’ll use 2 6mm wheel spacers I’ve got lying around on the rebuilt shaft and leave the other side as is. The difference of 12mm on the offsets of each side shouldn’t make that much difference as a temporary measure until I can get a sensible set of 10mm spacers that fit.




Extended Wheel Stud Fitted

10mm Wheel Spacer

Spacer Won't Fit Flush

 

Half shaft rebuild underway

Still waiting for my rear wheel bearing to be delivered, card through the door from the postman while I was at work so I'll pick it up from the sorting office tomorrow. In the meantime I set about getting stuff ready to rebuild the halfshaft assembly.

I've decided to replace the outer driveshaft as well just in case there is something wrong with it which was causing the bearing issue. I had a choice of 3 2nd hand spares so I chose the best one, in particular the one with the best thread at the end which is a weak point. I've got a die nut the right size for the thread so I also ran that down the tread to clean it up nicely.

Replacing the outer halfshaft means the rotoflex coupling has to be removed, the coupling fitted is still in very good condition, however I had one brand new genuine metalastic rotoflex coupling in my stash of spares so I decided to rebuild the halfshaft using this. I now have two 2nd hand but good condition genuine metalastic rotoflex couplings in my spares stock. Although it would be a bit of hassle to refit these if I need a replacement as they don't have the temporary steel compression band in place that new ones do it would probably still be better to do that than fit pattern ones which wear out in 5 minutes and new genuine ones are now well expensive so I'll keep and cherish the used spares!

I've also ordered some extended wheel studs and 10mm wheel spacers which should resolve the issue I have with limited clearance between the cosmic alloys and the lower wishbone bush shrounds. Easiest to fit these while I've got the hub off although I'll change the studs on the other side hub in situ which probably means stripping out the brake shoes etc but no big deal.

So tomorrow once I get the bearing I can measure up and find out which distance piece I need to buy to set the bearing end float in order to be able to finish the job.

Shaft rebuilt with replacement outer shaft and new metalastic rotoflex xcoupling. The UJ was replaced 1000 miles ago so I've left that well alone. (Must get around to tidying up my messy workbench sometime!)