teletech Posted December 23, 2022 Share Posted December 23, 2022 I had a thread for acquisition, but on to installation and it seems like that could use it's own thread. The vehicle I'm working on presently is a diesel, someday I'll do my petrol one, but not for a while yet. I've got the gearbox sitting in it's spot, I do not have the centre bolt or shims as yet. I've set the angle per the document referenced below, but that results in the propeller shaft from the motor being about 3/16" low. So, either I've got the gearbox wrong, or I need to raise the motor. At present the space I'd need to fill for the centre bolt spacer is 1-3/8". I also could use help with the gearbox oil line routing, generally and in-particular it seems the oil level dipstick would interfere with the hose coming from the oil filter housing. Here's the note saying the input face of the clutch should be parallel to the bulkhead/fan: transmission-to-fan-alignment-Craftsman-MARCH-2016.pdf Quote Link to comment Share on other sites More sharing options...
sirhc Posted December 23, 2022 Share Posted December 23, 2022 Do you have this manual? https://www.greenmachinesurplus.com/cvrtx28dx29repair-instructions-common-items-522-2897-p.asp I built my Scimitar from a pile of bits. My engine mounts were missing. I was told to make sure the top of the gearbox (yellow, red or blue plate with the filler plug) is level with the sponson (horizontal bit of hull above the tracks) - I did this using a spirit level and making sure the vehicle is on level ground. I did have the shim pack and conical washers so it was very straight forward. The double check is to put the fan bulkhead in and measure the distance from the gearbox pulley to the bulkhead at the top and bottom. If it’s not the same your belt won’t last long. The engine mounts are also shimmed using basically different thickness washers. I had some laser cut in varying thicknesses. I then borrowed the alignment tools to get it at the right height. The back of the engine (not flywheel end) should be slightly higher than the front to prevent the drive shaft from falling prematurely. The engine went in and out 2 or 3 times to get this right. I’ve not had to touch it since I fitted it in 2013 and I’ve never lost a fan belt, so I think this method works. Quote Link to comment Share on other sites More sharing options...
teletech Posted December 23, 2022 Author Share Posted December 23, 2022 No, I do not have that manual, but now I know where to find one. Pity about the shipping delay and such as I have several days off to play with my CVR(T). interesting to think the sponson was considered a trustworthy datum, but perhaps that what they used before the article I found. All sources agree the fan shaft and clutch drum running parallel is critical at least. Did you shim under the mount frame (between the hull and engine support cradle) or at the top of that cradle, below the shock-mounts? I'm looking up torque values now, but considering the weird aluminum they used in these, I wonder if I should use usual values? Quote Link to comment Share on other sites More sharing options...
teletech Posted December 24, 2022 Author Share Posted December 24, 2022 1 hour ago, sirhc said: . I did have the shim pack and conical washers What are the conical washers, are we talking belleville washers or spherical washer sets? Quote Link to comment Share on other sites More sharing options...
sirhc Posted December 24, 2022 Share Posted December 24, 2022 I think the following pictures show the value of purchasing the correct manual. Chris 1 Quote Link to comment Share on other sites More sharing options...
sirhc Posted December 24, 2022 Share Posted December 24, 2022 You should also buy a copy of the diesel common items parts list. Quote Link to comment Share on other sites More sharing options...
teletech Posted December 24, 2022 Author Share Posted December 24, 2022 9 hours ago, sirhc said: I think the following pictures show the value of purchasing the correct manual. Oh, indeed! I'll have a copy of the manual coming as soon as I can get one on it's way, shipping internationally this time of year is going to be a challenge though I suspect, so I do very much appreciate you sending me that illustration to tide me over. I'd actually purchased a copy of the parts manual, but it came without the section on the gearbox. So, spherical washers top and bottom of the fifth bolt, That's what I'd have imagined as making sense, but what makes sense to me and a proper mechanical engineer are sometimes different things. Quote Link to comment Share on other sites More sharing options...
teletech Posted December 27, 2022 Author Share Posted December 27, 2022 On 12/23/2022 at 3:10 PM, sirhc said: The back of the engine (not flywheel end) should be slightly higher than the front to prevent the drive shaft from falling prematurely. I'm curious, you don't happen to know the rationale for this? the idea that the crankshaft should be at a slight angle to the gearbox input shaft rather than making the best effort at parallel seems strange and that the direction of the angle matters is even odder. I guess one could argue that the shaft will never be truly parallel and coaxial and so a constant preload on the joint is better than an intermittent one, but that still isn't a help about why one end of the motor should be higher than the other. The flywheel-side bolts aren't bad, but the one under the injection-pump isn't a great deal of fun to access. Quote Link to comment Share on other sites More sharing options...
Andrew Rowe Posted December 27, 2022 Share Posted December 27, 2022 When you say the back of the engine slightly higher to stop premature failure of driveshaft , was this on the early model ones that actually used a short solid driveshaft?, ( This is to preload the UV crosses ? ) This early coupling was replaced by the later rubber donut , so I would hazard a guess, that this ( Donut Coupling ) should be mounted parallel in all directions and plains, just like our rubber inserted Bren carrier gearbox to diff joints , other wise you DO get premature failure of the rubber components because of any misalignment , cheers Andrew. Quote Link to comment Share on other sites More sharing options...
sirhc Posted December 27, 2022 Share Posted December 27, 2022 12 minutes ago, Andrew Rowe said: When you say the back of the engine slightly higher to stop premature failure of driveshaft , was this on the early model ones that actually used a short solid driveshaft?, ( This is to preload the UV crosses ? ) This early coupling was replaced by the later rubber donut , so I would hazard a guess, that this ( Donut Coupling ) should be mounted parallel in all directions and plains Hi Andrew, No the diesel drive shaft is different, it’s much larger and heavier. https://cvrtpro.com/shop/cvrt-engine-parts/diesel-specific/cvrt-coupling-main-drive/ Chris Quote Link to comment Share on other sites More sharing options...
Andrew Rowe Posted December 28, 2022 Share Posted December 28, 2022 Oh yes, I was thinking of the Petrol J60 combination, Cheers Andrew Quote Link to comment Share on other sites More sharing options...
teletech Posted December 28, 2022 Author Share Posted December 28, 2022 It feels a lot like measuring Jello. first the spirit level technique to align the gearbox, then the motor needs to come up quite a bit. Then use a different level and find an irregularity in the bulkhead attachment flange, so re-level the gearbox and lower the motor half-way. Then fit the bulkhead with the fan and check to find the shafts aren't parallel and the gap uneven, so re-shim gearbox and lower the motor further, then realize the bulkhead is going to be shifted by the installation of the top armour... In the end, I set it a few thousandths off with the understanding that things will shift a bit when the top goes on and that there is some bend in the bulkhead mounting, there is some chance I'll have to shim the blower a few thousandths to compensate. Moving on. A friend did have a suggestion about why it was suggested the driveline should be set up with a slight angle in one direction but not the other. His idea is that it's set up that way to account for flex under load. I'm not satisfied with the idea, partly because I don't imagine very much hull flex considering the thickness of the material and construction, and partly because if anything I'd expect one to need to load things in the other direction. So, I still have no idea why they don't instruct one to set the crankshaft coaxial with the input shaft. Quote Link to comment Share on other sites More sharing options...
teletech Posted December 29, 2022 Author Share Posted December 29, 2022 On to hoses. I've got one really nice hose, but the other two are very poor. I'm looking for hoses for sale, but also investigating other in the hopes of moving things along. I took them into a local shop and they had no idea what the fittings were, so that necessitates salvaging the existing ends, which can be a really challenging job in part because the hoses are set up for 1500PSI pressure handling. I confess, I don't understand that even slightly. From what I've found in the manual it appears the working pressure of the gearbox is internally regulated to 45-50PSI. Am I missing something? Quote Link to comment Share on other sites More sharing options...
teletech Posted January 5, 2023 Author Share Posted January 5, 2023 Tensioner - Fan Belt - AS39786 I need one of these, I posted a want over in classified and have reached out to the outfit that sold me the gearbox, but nothing as yet, so unless someone here has one to offer, I'm wondering if it might be easier to just fab one. Drawings or dimensioned pictures would be welcome and appreciated. I guess mostly I'm wondering if there is any magic inside the roller or if it's just a cylinder with bearings in? Quote Link to comment Share on other sites More sharing options...
robin craig Posted January 6, 2023 Share Posted January 6, 2023 I think, knowing you and your skills, if you use the bolt holes where this mounts and the size of the belt that you can fabricate one from dimensions you can gain there that would be fit for purpose, don't under sell you skills. Quote Link to comment Share on other sites More sharing options...
teletech Posted January 7, 2023 Author Share Posted January 7, 2023 2 hours ago, robin craig said: I think, knowing you and your skills, if you use the bolt holes where this mounts and the size of the belt that you can fabricate one from dimensions you can gain there that would be fit for purpose, don't under sell you skills. Turns out, the vendor I got the gearbox from was on holiday, but is back and has offered to fill the order for all the parts I need. That tensioner was by far the most expensive part and I was tempted to fab one, but since I have enough to do and a few of the other parts weren't as bad as they could have been, I decided to just spend the money. I've got the hydraulics overhauled and refit, so the list of needed tasks is getting very short indeed and quite soon the biggest challenge will be clearing a path from the Spartan to the door... well, that and learning to drive. 😄 Quote Link to comment Share on other sites More sharing options...
teletech Posted June 15, 2023 Author Share Posted June 15, 2023 The vendor got very busy with orders from Ukraine for several months, but they did finally send me the bits I needed to get things going. I've finally got the hoses on, gearbox filled with oil, brakes bled, and many of the other small tasks that needed doing. At the moment I think my biggest hurdle is still a path to the door. Lots of little tasks though, but making progress on them as well. 2 Quote Link to comment Share on other sites More sharing options...
teletech Posted June 18, 2023 Author Share Posted June 18, 2023 Well, so much for my alignment.... I finally got the vehicle assembled enough to get the cooling system working and ran it for a while. It seems my fan belt alignment is not good. I'd carefully checked the distance between the bulkhead and gearbox flange, but that was with the decks off and it appears the installation of the decks pulled the bulkhead out of alignment. Whatever the case, I'm seeing unacceptable wear on the fan belt against the back (fan side) flange of the fan pulley. I guess my choices are raise the back of the gearbox or shim the fan, unless I'm missing something? Quote Link to comment Share on other sites More sharing options...
Diana and Jackie Posted June 20, 2023 Share Posted June 20, 2023 (edited) If the belt is rubbing on the fan side (ie Engine side) of the fan pulley flange you need to lower the gearbox by removing a shim from the gearbox holding bolt. This is the worst possible design I have ever seen, the belt position as I discovered can be altered by many variables, including belt tension! Edited June 20, 2023 by Diana and Jackie Grammar 1 Quote Link to comment Share on other sites More sharing options...
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