» » »

GMC Q&A

Ask Your Question

1990 GMC 1500 Pickup Question: Manual Transmission Oil

 

Question

Alaska GMC, 5.0L V8, Anchorage, AK, June 26, 2009, 11:02
 Rookie

Hello Team,
I recently purchased a used 1990 GMC 1/2ton pickup (SL Sierra) with a 5.0L engine and 2wheel drive and am seeking to determine the proper gear oil to use in the 5 speed manual transmission, what do you recommend and why?
Thanks,
Alaska GMC

2 Answers
Flag This
  • Answer #1

    Russ June 26, 2009, 13:12
     Master

    The recommended gear oil for your 5spd gear box is something called - GLS; GM part no. 12345349. I have not been able to find an specific information on GLS anywhere. I would suggest to check with your local GM dealer and see what the recommend for your area. The requirements in Alaska may be a bit different.

    Reply
    Flag This
  • Answer #2

    GMGunner July 13, 2013, 13:37
     Rookie

    GM Performance 88900333 Synchromesh Transmission Fluid

    Reply
    Flag This