Crashtd420 Posted May 11, 2018 Author Report Share Posted May 11, 2018 Well after a couple days of driving came up with my first issue.... Speedo is about 10 mph off... it's showing faster than I am actually going.... I guess I'll be pulling the Speedo gear to see what I have.... I do have a second 4spd in the basement so I'll be pulling that one out for comparison.... hopefully they are not the same.... Motor has been perfect, temp has been at the middle line, seems to like the carb... I still wanna check all the plugs... I pulled one quick yesterday and it looked good... Probably should check the valves soon too... 2 Quote Link to comment
mainer311 Posted May 12, 2018 Report Share Posted May 12, 2018 My speedo reads high too. Even worse with the slightly smaller tires. Was driving the roadster on Thursday afternoon, and the stock temp gauge pegged high. Normally I’d be concerned, but my brand new auto meter gauge was reading 160. Driving old Datsuns is always an adventure. 1 Quote Link to comment
DanielC Posted May 12, 2018 Report Share Posted May 12, 2018 On a 521, if either the temp gauge or the fuel gauge is pegged high, and you know the temp is normal. or the tank is not full, the wire to the sender is shorted to ground. 2 Quote Link to comment
Crashtd420 Posted May 15, 2018 Author Report Share Posted May 15, 2018 Ok so what's the trick to removing the Speedo pinion gear assembly from the transmission?.... also will it leak?... i'm thinking if I jack up just the driverside it will keep it from leaking... They seem pretty snug, pliers and screw driver wasn't working, but I didn't get too aggressive with my attempt, i figured I should ask first... I trying to pull the ones in my basement so I can figure out the process before I'm stuck under the truck trying to figure it out... 1 Quote Link to comment
DanielC Posted May 16, 2018 Report Share Posted May 16, 2018 The speedometer pinion holder is just held by the little tab, that is in a slot in the holder. It is sealed by an "O" ring in a groove in the pinion holder. If you remove the speedometer pinion holder out of the transmission still in the truck, expect a lot of oil to pour out. You might be able to prevent loss of oil by raising the rear axle of the truck, so the rear of the transmission is higher than the fill hole on the side of the transmission. 1 Quote Link to comment
Crashtd420 Posted May 16, 2018 Author Report Share Posted May 16, 2018 I got that far.... should these just pop right out? Do you need a special puller? I'm soaking the one in the basement with Pb Blast... thinking the oring is what's holding on.... 1 Quote Link to comment
Crashtd420 Posted May 16, 2018 Author Report Share Posted May 16, 2018 Does anyone know the threads size on the speedo drive? I'm thinking I can make an adaptor to connect to a slide puller I have .... So while I'm trying to figure out how to get that Speedo gear out I figured I might as well ask another question.... I've been reading a few posts here about timing and it seems like you want full mechanical advance by the time you reach 3000 rpm... Is this true? I have a tunable distributor.. currently this is the curve I have programmed... Any input would be greatly appreciated... Side note... no vacuum advance, yet, i can program a vacuum curve too but I have it hooked up to manifold vacuum right now just to see if the info I'm seeing is even usable... no info programmed to the vacuum curve... Engine is the L16 bored to 84mm... 10.7- 1 cr.... w53 head, and a single weber 40 dcoe... Edit.... has a cam regrind too... 1 Quote Link to comment
mainer311 Posted May 16, 2018 Report Share Posted May 16, 2018 I have my L16 set to about 15 degrees at idle. That puts my total mechanical advance a little too high, but I run premium gas and haven't had any problems whatsoever. It also boosts timing at lower RPM in case the vac advance isn't doing what it should. Idle and throttle tip-in are much more stable with the advance set forward a few degrees. Your curve looks pretty good. Before I recurved my roadster, it was timed at 0TDC. It was such a dog. 1 Quote Link to comment
banzai510(hainz) Posted May 16, 2018 Report Share Posted May 16, 2018 speedo will have a 10mm head bold with a tab. pull that out and tug and wiggle it and it should slide out. My 521 was about 5mph faster than the GPS reading. But eventually I got another and put it in as the plastic teeth sheared off making it non operational.what was the metal shaft wasn't lubed up enough and froze thus shearing the round teeth part. can use the 510 ones but reading will be off as they are set for certain gear rations base on diff GR. My 521 speedo needle instrument panel is broke but the odometer still works fine so I can tell how many miles I got on motor 1 Quote Link to comment
Crashtd420 Posted May 16, 2018 Author Report Share Posted May 16, 2018 I was thinking I could tweek the curve better if all the timing was gonna be in by 3000... I can basically put 3000 at the Number 10 spot and that gives me more points to create a smoother curve from idle to full advance.... I can also push the whole curve up and down as I drive so I can try a little more or less at different rpms.. I'm basically trying to get as much power as I can out of this set up without messing it up.... 1 Quote Link to comment
Crashtd420 Posted May 16, 2018 Author Report Share Posted May 16, 2018 speedo will have a 10mm head bold with a tab. pull that out and tug and wiggle it and it should slide out. Ya the tug and wiggle thing wasn't working... I'll try again later and maybe i can get a better grip on it.... 1 Quote Link to comment
mainer311 Posted May 16, 2018 Report Share Posted May 16, 2018 I don’t get full mechanical on my Roadster until 4krpm, but compared to the truck, it’s a mini race car. 1 Quote Link to comment
DanielC Posted May 16, 2018 Report Share Posted May 16, 2018 Speedo pinion removal. Take the M6-1.0 bolt out, 10 MM head, that holds the tab, that holds the pinion holder out, remove the tab. Screw the cable nut back on the speedometer pinion holder. Grab the outside of the cable nut with a pair of vice grips. Get the pinion holder to rotate a little. Once it rotates a little work, it out of the transmission. Be ready to catch gear lube running out of the hole when the pinion holder comes out. 1 Quote Link to comment
Crashtd420 Posted May 17, 2018 Author Report Share Posted May 17, 2018 I don’t get full mechanical on my Roadster until 4krpm, but compared to the truck, it’s a mini race car. I'll probably leave mine at 4000 then... I did move a couple numbers and got a smoother curve on the graph... 1 Quote Link to comment
Crashtd420 Posted May 17, 2018 Author Report Share Posted May 17, 2018 Get the pinion holder to rotate a little. That's what it needed... once you said it could rotate i was able to break it free... they were definately stuck.... So I found a 17 tooth in my 63series 4spd in my basement, assembly was in great shape... And another 17 tooth in my 71b 5spd... but it is in rough shape, gear doesn't rotate smoothly.... Now tomorrow i'll pull the one out of the truck and see whats up.... really hoping its not a 17.. 1 Quote Link to comment
flatcat19 Posted May 17, 2018 Report Share Posted May 17, 2018 You know those gears are still available through Nissan, right? 1 Quote Link to comment
Crashtd420 Posted May 17, 2018 Author Report Share Posted May 17, 2018 You know those gears are still available through Nissan, right? I did not... that's good to know thanks... 1 Quote Link to comment
Crashtd420 Posted May 17, 2018 Author Report Share Posted May 17, 2018 I put the dash top on yesterday too, only 4 bolts, since I still have to do some small wiring and get the vents in... Mostly I wanted my extra gauges up and running... Rpm, oil pressure, voltage, air/fuel... Seems like I may need to upgrade the alternator... voltage drops to a low 13 when the electric fans come on and into the 12s once the lights and stuff are on... its charging at 14 when the motors cold, so I just need some more amps.... Also, i had a big hole in the side of the muffler the other day which I patched, but I think the baffles are rotted out inside ... just to loud right now when I get above 3000 rpm.. Hopefully this will be better.... 2 Quote Link to comment
banzai510(hainz) Posted May 17, 2018 Report Share Posted May 17, 2018 I thought those gears were sold out a long time ago. esp for the stock gearing. as for the shaft not turning ez. I pulled mine out and used some fine sand paper stuck it back in the olderand now it works fine and ez to turn. Altanator on 521 . the 35amp fits the best.. I had a 50amp but always had proplems as the smaller L16 bolts always would work out then busted flush in the block. I went back to the 35amper as had more adjustment room with my turnbuckle tension set up. As for mufflers if I do it again I will swap out my Dynomax Superturbo 1.75in to a Walker stock type same pipe size. As I only have a Weber DGV. I like quiet now driving as a 521 is so low geared and get buzzy on the freeway. 1 Quote Link to comment
Crashtd420 Posted May 17, 2018 Author Report Share Posted May 17, 2018 I thought those gears were sold out a long time ago. esp for the stock gearing. as for the shaft not turning ez. I pulled mine out and used some fine sand paper stuck it back in the olderand now it works fine and ez to turn. Altanator on 521 . the 35amp fits the best.. I had a 50amp but always had proplems as the smaller L16 bolts always would work out then busted flush in the block. I went back to the 35amper as had more adjustment room with my turnbuckle tension set up. As for mufflers if I do it again I will swap out my Dynomax Superturbo 1.75in to a Walker stock type same pipe size. As I only have a Weber DGV. I like quiet now driving as a 521 is so low geared and get buzzy on the freeway. On the Speedo gear the plastic gear is actually rubbing the body... it almost looks like the gear got pushed down on the shaft some how.... I'll keep that trick in mind... but since I have 2 I probably won't even bother with the messed up one... Biggest thing is getting the one out of the truck later and seeing what I actually need... The altenator i have right now is the stock 35amp.... its working, but I can watch the gauge drop once some electrical stuff comes on.... Not sure what route i will take with that.... right now it's not a problem just a concern.... And I agree on the quite driving.... i like to hear it but I also like to talk to my passenger.... I'll see how this sounds and go from there.... My old muffler was 15 years old so i bet this is gonna quiter regardless... 1 Quote Link to comment
Crashtd420 Posted May 17, 2018 Author Report Share Posted May 17, 2018 Another thing I noticed was after driving it around for a little while and hitting a bunch of bumps it looks like my front end settled a bit.... Seems like the passenger side is a bit lower than the driverside.... I'll try to make a quick adjustment while I'm underneath getting the Speedo drive out.... Other than these little issues things are running really good... It's so much more fun fixing small things and being able to drive it... 1 Quote Link to comment
banzai510(hainz) Posted May 17, 2018 Report Share Posted May 17, 2018 Yes the alternators are a little weak but I just learn to drive it differently. My H4 Highbeams and the Hella 500s(switch on at same time) drop the voltage at idle but I really never use the highbeams all that often the the battery should compensate while I use them for a short time. In winter is worse as one uses the heater and wipers but most times Im above 13.5 volts and 14 with 1 or 2 items ON. Suspension:sometimes the A arm I think whats its called the rubber bushing can wear out were the kingpin Dogbone is can be a issue but I think more camber one gets when they wear out. you might have replaced this already on your truck if I remember right just got my Rockauto order in 2 drums and shoes speedo and carb cable Looks like they will fit. wont know till day I need them Ngk wire set 1 Quote Link to comment
Crashtd420 Posted May 17, 2018 Author Report Share Posted May 17, 2018 Ya everything is new with my suspension.... I just need to crank the tortion bar up a little and even it out... When I first set the suspension up I had no point of reference to measure, I had to do this once already when I put the fenders on as they were just about touching the tire... 1 Quote Link to comment
Crashtd420 Posted May 17, 2018 Author Report Share Posted May 17, 2018 Ok so I found a yellow 16 tooth in my transmission.... I put the 17 tooth in and not much change probably 2 or 3 mph... moving in the right direction.... so I'm thinking 19 maybe 20 tooth is what I need... So how do I figure out exactly what I need? I know the rear diff is 4.37 gears... Tires should be close to original height... 195/60-15. Also will the correct gear in the 63 series 4 spd be correct to use in the 71b 5spd when I eventually get it installed. In the pic the yellow was in the 4 spd and the black came out of the 5spd, they seem the same.... 1 Quote Link to comment
Charlie69 Posted May 17, 2018 Report Share Posted May 17, 2018 Cut and pasted out of 1980 720 Factory Service Manual (FSM) Quote Link to comment
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