Silverbull3t

The new bearing caps have the C clip grooves in them. The original yoke has a flat area on the inside faces which I cleaned up with a hand file, the C clip sits up against this face on the inside of the joint, 4 places.

Thanks for the suggestions Bennie, let's see if I can address them all And yes I've been driving around with the rear half of the shaft out up until I got those new uni joints in the post. The vibe is gone with that out of the picture. Guess I can keep it in the back of the car when I'm en route to a destination then install it for the 4WDing part - broken/worn engine or gearbox mounts They were all brand new when I installed them, I did check the gearbox mounts at least withtin the last 6 months and they are fine/intact. Engine mounts, I will check. - modified gearbox mounts aren’t sitting true/have changed driveline angles They're the stock MY/Brumby mounts, bolted onto the L series brackets if I remember right which I filed the holes out oval shaped where they bolt to the sides of the gearbox. This is what Steve Rising sun (certified old subie guru) told me to do. Using the standard MY X-member. I never was 100% happy with this setup though. - rear output shaft bearings are toast in the gearbox, but this is usually accompanied with a leaking rear output shaft seal too (been there done that) I do suspect this gearbox (and diff for that matter) are trash, you could be onto something. The rear main seal isn't leaking though. (selector shaft seal is, dripping) There is another un-related weird low frequency wobble even in 2WD with the tailshaft removed, happens when I let off the throttle at around 80km/h or so. A bent internal shaft in the gearbox has crossed my mind. Amazingly that wobble went away with the tailshaft installed I'll be glad to get that new 3.9 box in there to compare. Does this vibration come on strong/quickly straight up when you start driving or does it work itself up to the vibration at set cruise speeds? It's weird is all I can say. Today I could feel it at 60km/h, then at 80 it was less severe but definitely still there. At 100 it is like a butt massage, get's worse from there. 3rd, 4th, 5th gear it seems pretty uniform. As for engine health, I should hope it's not that but it's not out of the question I suppose. Been meaning to do a compression test on it, it just feels too gutless (big wheels don't help) Maybe I didn't break the engine in properly? But it doesn't burn a drop of oil. Spark plugs I replaced a few months ago, old ones looked clean, good combustion signs. Can't understand that either, how it could be not running rich with the amount of fuel those twin carbies drink It might even be slightly lean as it pops/crackles on deceleration.

azdave, couldn't tell you why they went to two piece shafts except maybe because they could use smaller diameter tube, less chance the shaft could "whip" at high speeds perhaps. Well I knew it was too good to be true. The vibe is back Had 5 days of smooth driving to get my hopes up. It came back the day after I got back from that camping trip, as bad as the single piece shaft was when it bit the dust. I figured the second hand shaft uni joints were cactus (they were) so I got some greasable unis to replace them with, turned the staked joints into C-clip joints yesterday and today on all 3 joints. It is a bit better now but still definitely there, feels exactly the same as it did the first time I got this car on the road with the rear axles in it and that cursed single piece shaft. A low rumble at 100km/h / 60mph, will get worse as the speed increases. Right back to square one. Guessing it will gradually get worse over the next 18 months like it did the first time as the uni joints wear prematurely. And with this development I officially give up. The combination of this gearbox and diff in this car for some reason has un-solvable driveline angle problems. There will be a vibration always that can't be fixed, just have to live with it. I honestly don't know what I've done wrong that's so different to everyone else that's done a 5 speed swap. Unless they all have vibes too just people don't notice it? I dunno I currently have a 3.9 ratio 5 speed and rear diff at a local place being rebuilt. Going to get them to install it too because I don't have the facilities to do a gearbox swap at home. Might ask them to investigate the driveline angles while they're at it, get a second opinion, maybe they can suggest something to fix it. That won't be any time soon, but should be some time this year. There's an EJ20 swap on the cards too

Yes I was going to get a diff to swap in to see if it made any difference...except the only one in the wreckers yard was a 3.9 ratio! Ended up taking the gearbox home with me as well. Both will be professionally rebuilt then go into the wagon. Been a while since I updated this thread because I haven't done anything on it until now...the weekend before I'm due to go away on a 4WD trip next long weekend which I took an extra day off work for and everything. I've been driving the car with the rear axles removed for ages cos I got sick of the vibe and was at a dead end re fixing it. Well last weekend I had to replace the rear wheel bearings (not enough grease in them, they were howling) and decided to put the axles back in while I was there. Tried to get it up to highway speed that same day but couldn't because of heavy traffic. I got it up to highway speed about mid day yesterday and well...I thought the car was going to rattle to pieces. The vibe was worse than ever, so bad I couldn't see anything in the mirrors because they were shaking so much, high frequency vibration. So, I kinda freaked out because there was a 8+ hour road trip only a few days away... Ended up going back to the yard I got the g/box + diff from and taking the 2 piece tailshaft from that L series as well. Had to cut through a 10mm bolt with a hacksaw blade to get it out since the center bearing mount had spun the captive nut. And so my weekend went, yesterday and today frantically creating a center bearing mount for the 2-piece using what I had laying around. Was grinding till about 7:30 last night and I was back into it 7:30 this morning, got to test drive it about 6PM tonight (have to get to work tomorrow too, no stress!) well and truly tired and fed up. If it didn't work I probably would have cried. Instead I almost cried tears of joy because...the vibration is gone! Completely! 100% fixed. Couldn't quite believe it myself, have been fighting this issue for so long, 18 months probably. Amazing what a deadline will do in regards to motivation! Ended up going the crossmember style mount. It was made from 2" square by 1/8" wall tube and some 3/16" flat bar reinforcing. It's many times stronger than the floor it's bolted to. Not really happy with the strength of the floor. When I've got more time I'll make up a strap out of flat bar that hugs the tunnel on the interior and join the two mounting nuts together. At the moment I welded the nuts to some large square bits of 3/16" plate to spread the load a bit.

I rang the tailshaft shop during the week, a double-cardan joint is a no-go apparently, too much work to adapt things they don't want to do it So after I clocked off on Friday at work I jumped on the lathe and knocked out 4 spacer blocks for the torsion tube/rear subframe, 10mm shorter than the ones that were in there. They are a bit small (largest scrap round bar I could find) but I figure they were a quick temporary thing to test my hypothesis, if it works out then I will go to some more effort and make something a bit bigger. It was an easy job to get them in, just did one side at a time. I measured the angle of the pinion drive flange before and after, the difference is about 1 to 1.2 degrees. Lets say the operating angle of the rear uni is now 2.4 to 2.6 degrees. This is with a 5mm shim underneath the moustache bar lift blocks as well, so 15mm difference front to back, 0.6 inches roughly. The ride height in the rear is now 10mm lower as well, rear tyres are 10mm closer to the body, which is annoying but I don't think I can put 15mm shim under the moustache bar only or the diff would hang lower than stock! Went for a quick drive, no rear axles in place so I drove it in high range. The vibration seems to be gone or at least not noticable with no axles in. What is noticeable however is the howling and whirring noises coming from the rear diff when I'm on the throttle...I think this diff is junk Or at least the bearings in it are toast. Couldn't pick it out amongst all the other noises and vibrations before I started this journey. I'll have to get it or another one rebuilt to swap in. There is also the low frequency wobble that happens in 2WD that I wrongly attributed to the tailshaft before, only now it occurs to me I never got a wheel alignment done on this car It doesn't crab sideways or scrub the tyres so I never put it on the priority list, perhaps that was a mistake So one step forward two steps back...

Jonno, I'm definitely not removing all the 4WD gear and only having 2WD, this whole build was meant to be a 4WD from the start Bennie, they are stock MY gearbox mounts on the stock MY crossmember. The small metal brackets between the mount and the box had their holes elongated so it would bolt up. Dying uni joint is a possiblility, but unlikely since I had this vibe from the moment I put the rear axles in a year ago. Maybe driving it like this for so long has killed the unis too, joy They're not the greasable or rebuildable type. Balancing is a step beyond a normal build I know with added cost, the build wasn't very expensive anyway. This twin port is the most lumpy/bumpy EA81 I've driven, it is an old engine after all that's been rebuilt more than once in its life. Doesn't stop me from enjoying it, it still makes me smile sometimes skishop, everything you said is everything I suspected about the operating angles etc. Adding a double-cardan to the rear never occurred to me, that could be an easy (if not expensive) way out of the issue. Would also have the car off the road for a week or two which is not ideal as it's my daily driver The shaft was built by the only place in town here that makes tail shafts so I would hope it was done right, it has balancing weights on it and the yokes are 90 degrees apart. For experiments sake, I'm back to the idea of reducing the lift block height at the torsion bar mounts to bring the nose of the diff up. Need to get a free minute at work to part off some 40mm long chunks of 50mm dia. aluminium on the lathe. All this talk when I could just bash two holes through the floor pan and use the 2 piece shaft

It's been a while since my original post, been busy with life and other things. I have done a couple of things in that time however. Swapped the rear axles left to right - made no difference at all to the vibration Today I removed them completely - the main vibration issue is gone, it's a much smoother ride now the tailshaft isn't spinning. Engaging 4WD with no axles as Bennie suggested, the vibration returned albeit less severe I guess since there's less spinning mass with the axles missing. Disengaging 4WD while on the move and the vibration magically goes away. Side note: don't try and engage 4WD while moving with no rear axles installed; the tailshaft is not spinning but the gearbox is so there is an almightly crashing grinding sound It was an interesting drive for other reasons too, now I am aware there are many other vibrations and shudders from different places at different times Most of which I previously attributed to the tailshaft. For example; Low frequency shudder when off the throttle/coasting in 4th or 5th gear at say 80 km/h or above. Shudder goes away when back on the throttle OR pushing the clutch pedal in. When the engine is loaded up in 4th or 5th gear e.g WOT but not gaining speed there is another low frequency vibration from the engine. Rear wheel bearings are making noise and a slight vibration during sweeping turns at speed. Car seems to have a bit more pep now the rear drive parts aren't being spun up. I'm really kicking myself I didn't specify to get the engine rotating assembly balanced properly when the engine was rebuilt. This engine makes so much vibration and shakiness, it is not smooth by any stretch of the imagination. Even the idle is incurably lumpy and shaky In any case, I can work to address the worst vibe which by far was the tailshaft and go from there...

Copy/pasting across two forums for anyone else reading... That's a good idea to narrow it down, remove both rear axles and drive it in 4WD. To achieve a similar result I had thought of removing the tailshaft (easier than removing axles) and going for a drive but I don't have anything to plug up the back of the gearbox at present. We're going back 12 months now in the memory bank; when I drove it without the rear axles in (2WD mode) there was no vibration, it only appeared after I put them in, I don't suspect the front axles. It happens all the time regardless of on power or coasting, in gear or neutral. Gets worse with more speed, if anything I might say it's slightly worse when coasting. The rear axles are genuine AFAIK I got from a U-pull it wreck then had rebuilt at a good CV shop, they look like new now. Had to beat the ever living hell out of the inner cups to get them off the donor diff, is it possible to deform those? Then again the frequency of the vibration is much higher than wheel RPM so maybe not the CVs. -The rims are a nice snug fit on the hubs, I got adapter rings to ensure that. -The diff is a possiblity, although the vibe was there with the stock spider gears and no different after the locker went in. Didn't notice anything bad when I had the diff apart. -Rear CV shafts, also possible but I had them rebuilt professionally. -The locker isn't ratcheting during the vibe, unless I go around a bend then I can here a slow click, click, click which is normal. Tyre pressures are equal. I hope we're getting a trip report with piccys of this 4wd trip

Should have mentioned, the vibe-free driving with missing rear axles was back when it was an open diff, I've got the Torq locker installed in my wagon now Jonno Not sure how it would go with 1 axle missing I imagine it would be ratcheting constantly. Might have to take both axle out and I never could get them in or out without unbolting the bottom of the shock absorber and the 3 bolts to the torsion spring, let the control arm sag as far down as it could possibly go to get enough room to swing the axle in. Not fun on the side of a dirt track. Not keen on grinding my stub axles down either Rather fix the driveline angles so it's all working as it should be, thinking of a way I might be able to slot the diff hanger bracket for adjustable pinion angle...or an offset hanger bushing maybe?

I'm currently investigating weird driveline vibrations in my resto'd wagon, it has the L series 5 speed D/R with a custom single piece tailshaft to the L series rear diff. The main vibe I'm chasing is the one that appears in the rear at highway speeds, around 100 km/h (60mph) and above it gets worse and worse the faster I go. It goes away if I take a rear axle out and the tailshaft no longer spins. Super frustrating because I want to do some longer camping trips but feel like I can't because of this. I got myself a digital angle finder yesterday and tried measuring the driveline angles of the front and rear uni joints on the tailshaft. Has anyone else gone through this process? I get different results measuring off of the uni joints (tailshaft installed) compared to measuring directly off of the diff/gearbox with the tailshaft out. In any case there appears to be a difference of 6 degrees between the gearbox output and rear diff input, making the operating angle of the rear uni joint 3.6 degrees approx which is no good. Front is not as bad, around 2 degrees. The gearbox output is pointing down fairly steeply. The front of the rear diff is more flat, needs to come up to match the box. I think I'm only having this issue since I'm running the single piece shaft, most other people AFAIK are using the 2 piece shaft which I think would absorb more of this difference in angles and not vibrate at high speed. Having thought long and hard about going to the 2 piece, I decided to try and fix the issue with the single piece, don't want to pull up my carpet and sound insulation to weld or drill into the floor pan. This car is my daily driver. My plan for the fix so far is to slightly shorten the lift blocks that the torsion bar/tube is mounted to and extend/shim the blocks that the moustache bar is mounted to in order to angle the diff some more. Watch this space for results. Changing the gearbox angle is a no-go; shfiter mech binds up before I get even 1 degree of adjustment. Interested to know if anyone else has run into this issue and if/how they rectified it.

Seems to me like there may have been more than one issue going on here. I would put money on it though that your fuel filter (wherever it is) is blocked and needs replaced. Maybe even the fuel lines are blocked too or the pump is faulty. If it was me I would remove the fuel hose from the carburettor, put it in a jug/bottle to catch anything and then turn the key to "ON" make the fuel pump run, see if anything comes out, it should be healthy flow rate. It having sat for so long and then suddenly run regularly again has a tendency to wreak havoc on the fuel system. I must have missed it along the line somewhere, did you do a compression test through all this?

My guess is the previous owner has added that relay to bypass the ignition switch (they do get crusty and stop working at this age or have big voltage drop) I've found a couple of pages that might help, if the detail comes across in the pictures (2MB size limit means it's difficult to get high detail images across) The first one shows how the power should flow to the electrical equipment, all of the things you said weren't working at the start all come from the same line from the ACC switch. Second pic shows the overall wiring diagram in the battery area (this is an Australian/RHD model, might be different to yours) Dunno if this helps or not, I can't find that round connector (that the relay piggy backs onto) of yours in the wiring diagram I have here.

Something that hasn't been mentioned in here yet, 1981 model most likely did not have the black/grey fusible link box as has been shown in a few of these pics. I have a 1981 wagon and the original loom did not have it, the fusible links were literally two pieces of cloth covered wire coming directly from the battery + terminal. My 1984 ute has/had the fuse link box, I'm not sure when they brought it in. Before you ask, there's no point in me posting a pic of the wiring in my wagon since I've completely re-wired it. I've got a March 1981 factory service manual in my possession, I'll look through it to see if there is any helpful diagrams for OldieSubie. A question from me; what does the fuse box under your dash look like? Does it have blade fuses or glass tube fuses?

As Bennie says I had alternator issues this week, traced it to the LEDs I had put in the dash warning lights. Same thing would happen if your warning light globes were blown, no current going to the alternator field windings so no charging. Although I would think the slightly more modern L series would have a resistor across the globe filament so the alt would keep working if the globes blew. But it sounds weird as well and is getting hot, if it is the original alt then it may well be on the way out.

Thanks all, it's been a long project that's for sure. She's got 200 post-resto kilometres on the clock now as of today, I've been fiddling with the ignition map adding more advance bit by bit and wow is that twin port really coming alive now. And that L series front end swap has made a huge difference to the handling, it's a blast to drive. I'll put up a decent Youtube vid soon when I get around to shooting something.