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Now when I bought the car it was cold and 3rd didn't grind at all but after long drives and the tranny getting warmer it started to grind especially at higher rpms more and more and now your probably saying in your head oh **** I have the same issue .... Well at first I tried pennzoil synchromesh and the helped ALOT then went on a search for something better and there wasn't royal purple gear oil did nothing so I switched back to the pennzoil I topped it off then added LUCAS oil additive it says on the bottle for light duty trannys and no more than 20% so I over filled my tranny with the Lucas and let it mix while filling and let it drain from it being over filled .. After this I let my car warm for about 5 minutes then take off from the oil being alittle thicker than ussual after driving long distances it's gotten a lot better I still have to rev match 3rd when down shifting I don't think that will ever fix but the grinding is almost completely gone. Now for the high rpm shifts that will never fix honestly .. Please share your results or your method of "fix" open to different methods
planing on swapping the trannys anyways so this is just a hold over till then ..
You're putting a band-aide on a gunshot wound. Different fluid may mask a grind for a little while, but it's going to come back and it will cost more to fix the longer you leave it. Chances are you need a new 3rd/4th sleeve and hub and perhaps a 3rd gear synchro spring, leave it the way it is and you'll be looking at replacing 3rd gear itself as well.
First off whats with the ropelighting in the headlights?
As for your trans. Get that pennzoil synchromesh out of there. Its a "gear lube". most transmissions and differentials may use a viscosity of 75w-90 to like a 85W-140. Our honda MTF is basically some additives in a 10W-30. This is a MUCH thinner fluid. By putting thicker fluid in this will eventually eat up your mainshaft bearings. when Synchromesh was all the rage, lots of us screwed up our B and D trannies by using this fluid only to have our bearings make lots of noise between 6 and 12 months later. If the wear is just as bad with Honda MTF fluid then yes, you may need a new 3rd gear synchro and possibly a new third gear, depending on how bad the wear is. Also when you rebuild your transmission, go ahead and expect to replace all of the bearings. If you have a lot of metal shavings in it, check the runouts of the differential in addition to the clearences of your gearsets.
As for a bandaid fix, yeah Lucas is good stuff but expect this to work for maybe the next 3 to 6 months at the most.
For the cost of a D-series transmission, its cheaper to buy a used one, as they vary from 125 to 500$ depending on if you get from a junkyard or an online parts dismantler who will offer a warranty.
If you just added this fluid recently, for longevity, you may be better off running OEM fluid and just shifting slower into 3rd gear for now. This is the 'safe' way as itll last longer. the lucas/synchromesh way should feel better till it then suddenly gets very noisy (if you need to commute a long way and don't have AAA or somethin)
10w30 motor oil viscosity is measured at a much higher temperature than 75w90 gear oil. 90w gear oil is comparable to 40w motor oil. 75w gear oil is comparable to 10w motor oil. So 10w40 is very comparable to 75w90...so NO, gear oil is NOT thicker than motor oil at the same temperature.
the scale being used is set to thje expected temperature of the oil in use, in other words that gear oil is NOT running at the same high temp as motor oil is. the difference between the oils is the additive packages. a motor oil has additives designed to help the oil last longer at high temps, and the forces that bearings put on it, while gear oil has additives designed around the shearing forces of gears and the bearing loads there.
the grind is a physical problem in the transmission. For $130 i bought a syncro, bearing and seal kit and rebuilt my own transmission.
the grind is a physical problem in the transmission.
This is true. No amount of any fluid will permanently fix a transmission grind.
Originally Posted by v4lu3s
For $130 i bought a syncro, bearing and seal kit and rebuilt my own transmission.
Transparts kit? I hope you have better luck than other people.
As a rule the synchros are never really the problem in these transmissions. Most of what I see are sleeves and hubs that are scratched up and synchro springs that are flattened out. I've only ever seen one or two synchros that didn't have adequate clearance. Less often I'll see the engagement/dog teeth on gears rounded over, this is always in addition to a hub and sleeve being banged up.
Brake expert, you are totally mistaken on the pennzoil synchromesh. It's not thick gear lube and is totally comparable to motor oil viscosity. It works fantastic on DD transmissions, but does not handle high power or heat well.
94EG8, I disagree about the synchros. Just because the clearance measures in spec does not mean the synchro "brakes" properly.
Pennzoil Synchromesh I found to be garbage. It didn't do as well as even current day Honda MTF.
However, if you goto the GM dealer and get GM Synchromesh Friction Modified and also add a tube of MolySlip Molybdenum for Manual Gear Boxes, you have a pretty solid fluid that is designed for brass synchros and many of the same metals we find in our older Honda transmissions. I suspect it's much closer to the old Honda MTF of days of old.
07-24-2016, 10:27 AM
How my fixed my severe 3rd gear grind
