fredeuce

Duncan, Thanks for that. Much appreciated. Cheers, Fred

As the title to this thread topic suggests can anyone give me the diameter of the factory drive pulley for the power steering on the R32 Skyline ? We have an aftermarket setup on the front of the crank and the power steering pulley under drives the pump a bit too much for the street.

After reconsidering the approach to this issue as the PRP plate is already installed on the engine I went ahead and re-drilled the relevant four holes in the sump. Not straight forward with the sump installed but managed to get a reasonable result . My general concern about this is that the span created between the front engine mounts and the gearbox mount is considerable. With only half the bolts in place that is going to load up the top part of the bellhousing and make it more vulnerable to cracking. Some pictures of the result.

Has anyone had experience in installing one of these ? https://platinumracingproducts.com/pages/platinum-racing-nissan-rb26-wet-and-dry-sump-engine-cradle I am curious to learn of other peoples experience with them and their approach to mating up the gearbox and the four lower bolt holes which are now 12mm south of their original location on the engine. My concern is that welding tabs on the bottom of the gearbox means anytime you want to change the gearbox for any reason then you have to go through that drama of modifying the gearbox. My thinking is to make up an adapter plate 8mm thick and use 10mm countersunk bolts and bolt that adapter to the gearbox. The adapter would be patterned from the sandwich plate but have and have a 12mm longer bottom section to capture the new position of the holes in the sump. It would also have countersunk bolt pointing forward to go through the sump. The gearbox will now be 8 mm further back in the car compared to the usual installed position. Some issues: 1. Will the tailshaft accommodate this reduction in length on the CV joints? My observation is that it should be able to accommodate it. 2. The front tailshaft without any modifications appears to result in the shaft being withdrawn 8mm from the transfercase. That may result in the seal on the shaft not properly functioning. An 8mm spacer on the front diff flange would be appropriate. 3. Clutch fork needs to be spaced 8mm forward to restore correct clutch fork orientation. 4. The spigot on the front of the gearbox appears to have a wide contact surface so appears that it would accommodate running 8mm further back. 5. In a similar way the spline on the front shaft will run 8mm further back on the hub of the clutch plate. The clutch is a Nismo twin plate . The spline on the gearbox appear to protrude the front of the hub by about 5mm so would not fully engage the hub by about 3mm. Not ideal but should work. 6. Will there be sufficient clearance to the firewall? 7.Will the gearbox crossmember accommodate the gearbox being set back 8mm with some slotting of the holes? Look forward to your experiences with the PRP installation.

Setting up the timing belt on the sons engine following the rebuild. I am curious to know how the spring action is meant to work on these adjusters. According to the manual once installed the spring has the effect of pulling the tensioner pulley away from the belt. That seems counter-intuitive to me as I expected the spring to pull the pulley in against the belt. Is this how it is meant to work or are we missing something in the set up the spring / pulley ?

Having explored the original sizing of the alloy plugs these are 6mm and so do not suit a 6mm grub screw. I drilled to accept an 8mm dia x 8mm pug 1.25 pitch. After doing this and dropping the crank of at the machine shop for a linish he confirmed that he also fits 8mm plugs.

As the title to this thread topic suggests , can anyone tell me what size and thread grub screws are usually fitted to the RB26 crank to replace the pressed in factory alloy plugs? Cheers, Fred

Apologies , I omitted the pictures on the previous post. Here they are now.

Further to my previous post I attach some picture of the 5th gear assembly and the synchro cones that go with it. The first pic shows the tapered surface on the gear and the associated cone all of which goes to work when you engage 5th gear. The second pic show the second tapered piece that goes inside the coupler hub . You can see the taper is in the reverse direction. It appears the cone engages the tapered portion when you pull it out of gear. Can any one explain this?

Well after having the new bearing sleeve attachment made up , by my big brother who is a handy machinist these days( see pics) ,I fitted it up and was able to remove the sleeve first attempt without any further drama. All good! Now, the next issue is the rear thrust race on the counter gear . The manual shows a bearing plate attached and pressing the thrust race off together with the bearing sleeve. I am concerned that as the bearing plate captures only the outer edge of the thrust race that loading it up with a puller/press is going to distort/destroy it . What's the go here? See last pic. Next question. 5th gear synchromesh workings. I see there are two syncho cones associated with 5th gear. However on looking closely at them it appears that one cone operates when you engage 5th and the other appears to operate when you pull it out of 5th. Can any one explain the theory or workings of the 5th gear synchro arrangement? Cheers, Fred

BK the sleeve is about 6 mm thick and that allowed my puller to attach on the edge , not on the bolts. However observing the unit you had made up I think I will make a more robust version like yours with larger bolts and give it another go. I don't want to start using heat/welder as in the story in that link I posted.

BK, What you have is basically the same idea that I have utilized although I think yours is a bit more robust than mine. That said anything home made like this is still restricted by the size of the holes in the sleeve. They are only 5mm dia. and as your attachment illustrates the screws need to be turned down to fit the holes. As mentioned above my screws sheared off at the step down to the 5mm tips. If you have a look at the story on this link and the pictures attached this illustrates the problem well.It also show some fairly drastic last resort action in using a welder to heat/stretch the sleeve which of course becomes a throw-away item. I can only assume that the conventional methods of removal failed and then on to the welder.? http://takakenr.web.fc2.com/car2/mtoh/mtoh.html

I have progressed quite some way in dismantling this gearbox. I have now hit a stumbling block. The pictures attached show the rear portion of counter gear as it protrudes through the sandwich plate. You can see the 3 holes which I understand enables a special tool to be attached to the sleeve and then pull it off will a puller. I made up sleeve which you can see in the second picture however on attaching it with three stepped bolts I made to screw into the three holes all bolts sheered the tips off. It is clear this sleeve is very tight. I do not want to apply any heat to it. Any tips or other advice here would be appreciated. As a last resort is the factory tool readily available? The diagram of it in the manual is not clear as to how it works. It appears to be more than a simple sleeve with 3 pins spaced at 120 deg. Anyone have one of these that they can post a picture of ?

BK the essential purpose in going through the box is that the synchros are becoming slow and the gears crunch from time to time. That being the case then whilst it is apart a new bearing kit seems to me a good idea.

GTSBoy, Now that you and Duncan have confirmed this is a later pull style clutch. What I am proposing to do is to dismantle the gearbox and fit a new bearing kit. This is where CBC enter the picture as a possible supplier. Are there other suppliers of bearing kits for these gearboxes?