Jaccob

1990 Silverado K1500
4.3 V6
Manual 5 speed w/OD

RPO- MM5 AND Mg5
Number on transmisson- 8672306

Is it the NV3500 or the Getrag?

I might have damaged my tranny when I put Lukus 75w-90, when it should have synchromesh. I only drove it for a couple of weeks before finding out cost less auto gave me the wrong stuff. There is brass flakes when i drained the lukus, almost looks like gold in my pan, probably from the brass syncros?

Text me if you want, 360*952*0230 or you can call
If thats not acceptable to put my number in the forum, sorry, you can reply here too.

Richardx2

I have a NV3500 in my truck ao I am learning all about them,

the RPO code shows this:
MG5 Transmission, 5-speed manual
MG5 Transmission: Manual 5 Speed, New Venture Gear
MG5 Transmission – 5 Speed Manual (4.02:1) New Venture Gear
MG5 Transmission MAN 5 SPD, GETRAG, 84 MM, 4.00 1ST, O/D
MG5 Transmission Man 5 Spd, Getrag, 84mm, 4.001st, O/D
MG5 TRANSMISSION MAN 5 SPD, GETRAG, 84MM, 4.00 1ST, O/D

MM5 Transmission, 5-speed manual
MM5 Transmission, Aisin 5-speed manual
MM5 MERCHANDISED TRANS MAN 5 SPD PROVISIONS

Should be a NV3500

Jaccob

Only problem is that the Getrag 5l60m looks exactly like the nv3500, just different internals. I guess there were 4 different designs from 1988+ and the nv3500 I believe didn't come stock in those trucks until 1993.

Either way, my tranny is not a happy camper due to negligence on the auto part store. They gave me the wrong fluid, shifted funny, so I called to double check and he said he gave me the correct stuff. Turns out, 75-90 doesn't lube up the tight spaces in my tranny, and will also ruin my synchros. Synchromesh is recommended, which is 5-30, now its hard to shift and is not making nice sounds. ugh.

You think they have to replace it? Can I take them to court? Im sure in the heck gonna try.

Richardx2

The NV3500 also uses Syncromesh transmission fluid as specified by GM.



New Venture Gear 3500 transmission - Wikipedia, the free encyclopedia

The transmissions do have different configurations but it seems that GM wanted to have same lubricant for both transmissions.

I had the same problem with 2 nationally known auto parts stores try and tell me that the same lubricant for a early muncie type transmission transmission.

I feel the parts house has at least partial responsibility. Go up the food chain talking to manager after manager until you hit a brick wall. I have had success in the past be persistent.

Jaccob

Thank you! I knew about the syncromesh after running 75-90 gear oil for about 3 weeks. Luckily, the parts store is private owned and only have 3 stores. If they don't willingly replace my transmission, then I will send a letter of demand threatening to use legal action.

Wish me luck. Any of the getrag, new venture gear, and Muncie transmissions are pretty impossible to rebuild, and very expensive.

Richardx2

If you have to get a new one try this link I am going to put it behind my next engine. Best bet for money on that transmission for what you are getting.

http://www.smartpartsauto.com/manual...500_chevy.html

If you look on Craigslist remember the same transmission was used in the S10.