Saginaw question

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Saginaw question

Postby dindin » Thu Jul 12, 2018 9:28 am

I have a saginaw question not sure if it applies to all transmissions which is why I specify..anyway with transmission in neutral and clutch engaged does anything in the tranny spin besides the input shaft?

The reason I ask is a hear a whirr sound with clutch engaged..(Sounds very similar to a blower not crunchy or anything) in neutral... but it goes away when I push clutch pedal down.

..The tranny has been rebuilt and I used synthetic lube in it, I only took it up and down my driveway and have not road tested it yet, maybe thats why or maybe its normal, the car is much quieter than before so maybe I just never noticed the sound.

Al
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Re: Saginaw question

Postby Monza Harry » Thu Jul 12, 2018 10:37 am

Al all the gears spin all the time in a full "Synchro" [synchromesh] manual gear box, which the Saginaw is if memory serve me well, when you shift you are sliding the synchronising "clutch" or cone into mash and it matches the speed of the gear to the shaft as it engages. As for your noise I would suspect that the low friction [thinner] synthetic lube is making a difference in the noise you are now hearing and the quieter exhaust is letting you hear it better. As an addendum partial synchro boxes will have there gears as well just the non synchro gears will be free of contact that would be the older boxes that weren't synchro'd in first gear, and also full "Crash Boxes" will have the counter shaft spinning and that takes a pair of gears in contact, and all the bearings on that [countershaft] and the bearings on the input shaft and between the input and output shaft. And many stick-shift cars have a very noisy throw out bearing as well to add irritation/noise to the mix. Harry Here are a few video's not pre-screened for some FUN time viewing! https://www.youtube.com/results?search_ ... ssion+work
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Re: Saginaw question

Postby dindin » Thu Jul 12, 2018 11:12 am

Thanks alot Harry, Video of how synchromesh works explains it well.. :th:

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Re: Saginaw question

Postby cjbiagi » Thu Jul 12, 2018 10:18 pm

What kind of synthetic lub did you use? I did a lot of research on lubricants when I did my rebuild a couple years ago and decided not to use synthetic but rather stick with the recommended 80W90 GL-4 fluid. I used the "classic" lub from Brad Penn.

BRAD PENN® Multi-Purpose ‘Classic’ Gear Oil GL-4 SAE 80W-90

Brad Penn “classic” gear oil is specially blended to be used with “yellow” metallurgy (brass, bronze, copper) and other ‘soft’ metals used in components typically found in classic manual transmissions and transaxles.

Multi-Purpose ‘Classic’ Gear Oil GL-4 SAE 80W-90 Material Safety Data Sheet
Multi-Purpose ‘Classic’ Gear Oil GL-4 SAE 80W-90 Product Bulletin
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Re: Saginaw question

Postby dindin » Fri Jul 13, 2018 9:30 am

When the shop rebuilt the transmission they gave me a quart of Spectro oil fully synthetic gl-5, I did contact the Spectro at the time and about the gl-5 damaging certain metals and was told it was and old "wives tale"..I think I will see how it feels on the road ..I found an interesting video from a rebuilder about the subject last night..I actually bought some metal hurst shifter bushings from him a couple years ago after seeing the cheap plastic ones they come with kit.

https://www.youtube.com/watch?v=Z7NpsMZ9pBQ

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Re: Saginaw question

Postby cjbiagi » Fri Jul 13, 2018 5:19 pm

Ha, funny, I ordered the same bushings.........
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Re: Saginaw question

Postby 75Monz » Fri Jul 13, 2018 6:06 pm

Old wives tale or not, I've always had bad results running something other than synchromesh in a full synchro transmission. I didn't know any better and ran a gl5 in 3 of my geo metro 5 speeds. Took about 2 years each before they were trash. Old GM mechanic told me to run sychromesh since I didn't know what really was supposed to go in there and my current 2 are still nice and healthy after 5 years. The saginaw in my truck I ran a thinner synthetic in for about a year, it seemed shift harder for some reason, ended up swapping back to TH400 before trying different oil. I've never used anything since but the Pennzoil syncromesh and had no problems at all even in the real cold weather.
Check out this article I found that talks a little about oils in sycro trans, http://benmlee.com/4Runner/Transmission_Oil.htm . Not sure if the friction modifier thing applies to a saginaw or not since this article was mainly about toyota trans.
Bottom line from everything I've read, you need a good GL-4 if you can find it for a trans with yellow metals and synthetics seem to be a bit thin for the saginaws. Most of my saginaw problems are not related to oils, but are caused by my right foot I've been told. :lol:
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Re: Saginaw question

Postby Monza Harry » Fri Jul 13, 2018 9:24 pm

75Monz wrote: Most of my Saginaw problems are not related to oils, but are caused by my right foot I've been told. :lol:

:think: I'm willing to bet your left was a "contributing factor" Harry :oops: :haha: :cuss: :lol: :pook: :burnout: :burn: :oops: :rolleyes: :devil: :roll: lmao
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Re: Saginaw question

Postby 75Monz » Mon Jul 16, 2018 8:29 am

Surprisingly the left did his job correctly, the right on the other hand was a bit too quick on the "lift and mash" principle. :rolleyes:
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Re: Saginaw question

Postby Bullet » Mon Jul 16, 2018 4:47 pm

If it only makes the sound in neutral with the clutch out, it's more likely to be your throwout bearing. Put your foot on the pedal and just barely take up the slack and see if it goes away. If so, it is the bearing for sure since you haven't actually disengaged anything. A slight whirring sound is normal to a point but you may need to adjust your clutch linkage to pull the bearing back off the pressure plate fingers a tad.
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Re: Saginaw question

Postby dindin » Mon Aug 27, 2018 10:49 am

After driving it around some and listening to the noise it makes I decided to just drain out the Gl-5 and use the conventional Brad Penn Clyde used ..hopefully it will make it quieter..seems everything I do on this car I need to do at least twice.. :cuss:

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Re: Saginaw question

Postby cjbiagi » Mon Aug 27, 2018 9:37 pm

You also said "he gave you a quart" of oil. The trans takes 3
pints. So you need about a quart and a half. However, do not fill it all the way to the bottom of the fill hole. I suggest keeping it about a 1/2" below the hole. You should just be able to stick your finger in the hole and reach down and feel the oil. The reason I suggest this is the bottom of the fill hole is even with the shift shafts in the side cover. If the oil is too high it will seep out of the shift shaft seals, they are not designed to stop that much oil. So, you need the level to be slightly below them to prevent leakage. Let us know how you make out............
Last edited by cjbiagi on Tue Aug 28, 2018 10:29 am, edited 1 time in total.
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Re: Saginaw question

Postby dindin » Tue Aug 28, 2018 10:03 am

So I'm low a half quart, Thanks for the info

luckily I ordered 2 quarts, I could not find it locally..

the guy who did the rebuild put a drain plug in so its not to much hassle..

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Re: Saginaw question

Postby cjbiagi » Tue Aug 28, 2018 10:28 am

Correction on the capacity, it is actually 3 pints which is 1.5 quarts. If the car is level when you add oil I still recommend filling it to a little below the bottom of the fill hole. Having a drain plug is nice, in lieu of that you can pull the bottom bolt on the tailhousing.
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Re: Saginaw question

Postby dindin » Tue Sep 25, 2018 11:45 am

I finally got the oil changed out and put 1.5 quarts of the Penn gear oil, seems quieter not sure if it the oil type or because it was low a half quart before..

the only noise I still have if when I let of the gas and coast in gear I hear gear noise, if I disengage clutch it goes quiet,

I have not driven the car in so long I forget how it sounded before..feels nice driving it again though. :P

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