Manual Transmission Polaris Labs Test

[Scarpa]

Unfortunately Polaris labs PDF's will not let you extract a .jpg. Any thoughts, do you think this transmission might fail, there is a leak and it might have run too low on oil? Should I do the Analytical Ferrogram Polaris Suggests for $60.00?

Vehicle 1977 Datsun 620 pickup
4 speed Manual Transmission: Type F4W71B
Miles on oil: 37,153
Miles on Vehicle 112797
Date of Sample: October 2013
Type of oil: Probably 75W-90, should be GL4 but it might have been GL5, mfg unknown
Severity 3 report

Comments: We suggest that an Analytical Ferrogram be performed to clarify the type of wear and/or contamination that is present; Gear
and/or bearing metal is at a SIGNIFICANT LEVEL; Bushing/Thrust metal is at a SIGNIFICANT LEVEL; Abrasives (silicon/dirt) are at
a MODERATE LEVEL; Aluminum is most likely in the form of alumina/silica (Dirt); We acknowledge the COMPONENT
INFORMATION (type, manufacturer and/or model) was provided, however we were not able to validate it within our database or
from the manufacturer. Please contact the Data Analysis Department to clarify the information. Thank you. Please provide
missing lubricant information. Manufacturer, product name, and viscosity grade are needed to properly evaluate data.
Lubricant change acknowledged;

Iron: 869
Chromium: 7
Nickel: 2
Aluminum: 50
Copper: 19
Lead: 50
Tin: 18
Cadmium: 0
Silver: 0
Silicon: 35
Sodium: 6
Potassium: 0
Titanium: 0
Molybdenum: 0
Antimony: 0
manganese: 0
Lithium: 1
Boron: 2
Magnesium: 7
Calcium: 20
Barium: 1
Phosphorous: 1057
Zinc: 562

Water: less than .1 - Hotplate
Viscosity at 100C: 100cst
Acid Number: 2.89

 

[Rand]

its easy to get a jpg.
Just press the print screen button on the keyboard for a screenshot.

Then edit in paint etc.

 

[Jim Allen]

Are you noticing any shifting issues or noises that are not normal?

I haven't seen a lot of baselines for manual transmissions but since they are not filtered, you can expect to see more nastiness than with a system that has a filter. That said... there is a lot of nastiness in your sample. A ferrogram may or may not provide conclusive answers to anything, especially unless evaluated by a person familiar with manual transmissions in general and Datsuns in particular.

My advice, assuming, no adverse symptoms, is to determine the correct viscosity and GL grade of oil that should be installed, do a change and don't let it get low again. If you have an operational problem now, you know what to do.. it's overhaul time. If you are developing one, it will soon become clear and, again, you'll soon know what to do.. without spending $60 extra. Otherwise, you may have scoured some life from the trans but it may be OK with enough of the correct oil.

 

[Kuato]

Originally Posted By: Jim Allen
Are you noticing any shifting issues or noises that are not normal?

I haven't seen a lot of baselines for manual transmissions but since they are not filtered, you can expect to see more nastiness than with a system that has a filter. That said... there is a lot of nastiness in your sample. A ferrogram may or may not provide conclusive answers to anything, especially unless evaluated by a person familiar with manual transmissions in general and Datsuns in particular.

My advice, assuming, no adverse symptoms, is to determine the correct viscosity and GL grade of oil that should be installed, do a change and don't let it get low again. If you have an operational problem now, you know what to do.. it's overhaul time. If you are developing one, it will soon become clear and, again, you'll soon know what to do.. without spending $60 extra. Otherwise, you may have scoured some life from the trans but it may be OK with enough of the correct oil.


+1. A manual won't leave you on the road like an automatic can, it will give you plenty of warning that things are happening inside.

 

[MolaKule]

BITOG has a special forum for these reports:


Gear and Transmission Oil Analysis


If this was Factory Fill, it would be typical.

I suggest draining and refilling with either Amsoil MTG or Redline MT-90, both GL-4 MTL's with the proper additive package.

 

[Scarpa]

Jim Allen and Kuato, the shifting was as a bit notchy before changing the oil, it seems a bit better after adding the CRC GL-4, overall the gear shift is very loose with a lot of play, but it has been that way for a long, long time. Mostly the manual transmission seems to be shifting the same as always, but the Nissan Parts expert in California, Rod’s Datsun says it will shift that way until it stops working, unless I misunderstood him. I agree with you Jim, I am not sure a Ferrogram will help much in this situation, but I had never heard of that terminology until this oil report, thanks for the suggestions.

I put a UV dye in the Manual Transmission and Rear Differential to find the leaks, so far the only leak noted is out of the top of the transmission near the shifter, so I added another ½ oz of UV dye to each and am driving, waiting to find all the leaks. The hanger bearing went out, making the driveshaft loose which could have damaged part of the transmission such that might need to be replaced. I am using the dye to see if the leak is catastrophic to the Manual transmission before proceeding with the repair.

I used CRC SL2473 Sta-Lube GL5 80W-90 in the rear and CRC Sta-lube GL4 SL24239 80W-90 in the manual Transmission. I found this interesting thread at Ratsun.net about the importance of using GL-4 in those older Nissan Transmissions:

http://community.ratsun.net/topic/20936-manual-transmission-fluid/page-4

I used the CRC because it was not synthetic and less expensive; with the old seals it seems that a non-synthetic would be better? I want to evaluate the transmission and repair the leak before searching to see which better gear oil to use. At the time, I also was not aware that the better synthetic gear oils are still available in GL-4. The rear differential does call for GL-5, but the MT asks for GL4. I did submit a report to Polaris for the rear differential but it was only severity 1, so I thought that was not as interesting of a report to post?


Thanks to MolaKule for mentioning the "Gear and Transmission oil analysis" page, maybe the moderators will move my post.

 

[Jim Allen]

Good plan. I've had old manuals that were notchy in their old age and ran forever unless abused. The oil you installed is probably better than what was installed in 1977. With leaks, it probably won't be cost effective to install some expensive synthetic but it would be interesting to see how much better it might operate> "Might" being the key word., though I have seen some remarkable transformations in manuals with an improvement in the oil. Good luck.