COMPLETE: How long to change diff and manual trans oil?

[Teddydog]

My 2010 has just under 105,000 miles. I ordered it from the factory and took delivery in September 2009, so just about 8 years and 13,000 miles per year.

I have already had the brake fluid flushed. The only other major service items for 100k are spark plugs, differential fluid and manual transmission fluid.

I've been quoted $375-600 for the spark plugs (I understand a couple of them are a real b@stard to get to).

I have been quoted $130 for the rear diff and $100 for the transmission. These both seem high to me as well as being the opposite of what I would expect (the trans seems harder and takes 2x fluid). How do these prices sound to you guys?

I know that I could easily do these jobs (the fluids for sure) if I had the space, but my garage is way too cluttered to get the car in and my driveway is sloped.

The fluid for the diff and trans is 75W-90 Gear Oil. The manual specifies "GL5" for the trans and the diff needs friction modifier. Does this mean the same main fluid can be used for both and just add the friction modifier for the diff? I was thinking about using Mobil 1 Synthetic LS oil for both, but will the "LS" be an issue in the trans (Mobil says it already contains a friction modifier, but I would still use the GM stuff in the diff)?

Any thoughts?

I'm in the Puget Sound area of Washington State, btw.

Rob

[MIDNIGHTANGEL]

I thought the Spark Plug Changes were the easiest change I ever had to do on a car... They're slanted right on the top o.O

[Lil' Nasty]

Wow, that spark plug price is outrageous. I would get the OEM plugs on amazon and get a 5/8" spark plug socket if you don't already have one. As midnight said, they are very straightforward to change and are not difficult to get to. You simply unclip the harness from ignition coil, remove coil with 10mm socket and then take out spark plug.

You're got it on which fluid to use. I use amsoil 75-90w fluid in my M6 and royal purple 75-90w (the one that specifies already has friction modifier) in the diff.. I just like that the friction modifier is included in RP and Mobil 1.

[GamerDude]

Sparks plugs are so easy. Just have to remove the engine cover and a couple other things out of the way. I followed a YouTube DIY and did everything for under $50. You just need a 10mm wrench, a 5/8" spark plug socket, and 6 new ACDelco spark plugs and you're set. Coolant should have been changed and replaced 3 years ago. As the manual says, replace coolant at 100,000 miles or 5 years, which ever comes first. Dexcool coolant is known to sludge up after 5 years so do that too if you haven't already done so. Definitely do the transmission and differential fluid change.

[Teddydog]

Wow! Thanks, guys. I've done spark plug changes in many cars before. I could have sworn I read that a couple of them in the LLT were very hard to get to. I have now watched a video and it is clearly a simple process! I'll definitely do these myself.

The fluids will still be a challenge without a level place to work and/or lift the car.


Rob

[its a syn]

This engine is not something to get scared about. So many you tube vids out there. In 2 years you will dive into projects that will be so easy to get some horsepower . It is only scary when you end up with unexpected parts lol!! Get your knuckles bloody You will be fine..

[Teddydog]

I just found a self-serve garage with lifts in my area! That means I can do the transmission and rear diff myself! I'm very excited about this discovery.

The lift bays rent for $20 per hour. Will 1 hour be enough time to get the transmission and diff? I would think so.


Rob

[djrasras]

Originally Posted by Teddydog

I just found a self-serve garage with lifts in my area! That means I can do the transmission and rear diff myself! I'm very excited about this discovery.

The lift bays rent for $20 per hour. Will 1 hour be enough time to get the transmission and diff? I would think so.


Rob

Even if you are doing everything for the first time, it should definitely not take more than 1 or 2 hours to do fluids and plugs as long as you watch some quick vids before and know where the drain bolts are beforehand. Only issue I ever had was the siphon thing I got from Harbor Freight was crap and the first time I did Tranny fluid change the hoses kept unsecuring... regardless it was still done quickly, just a bit of mess cause it was my first time. Self-serve garages sound awesome though

[Teddydog]

Thanks. I have looked at some pics/vids and know where the drain and fill plugs are. And I know to remove the upper fill plug first!

I'll do the plugs at home in my driveway. No need for a lift for that.

Rob

[Teddydog]

Thought I'd post an update about my maintenance. The self-serve garage worked out great! I took my time with the trans oil and diff oil change and it took about an hour. I'm sure I let them both drain longer than needed. Pumping the oil up into the fill holes was a bit of a pain, but overall the process went really well. Total cost was $24 for the shop, $47 for the Mobil 1 oil and friction modifier and $10 for the pump (which is still usable).

The new Mobil 1 synthetic oil in the transmission seems to have made a difference--it is a bit smother shifting from 1 - 2 and 2 - 3.

No noticeable change from the diff.

The self serve garage charges just $10 for a half hour for an oil change, so I'm planning to going back to doing those myself, too.

Spark plug change planned for tomorrow!

Rob

[Ventmaster]

You go Teddydog! Doing your own maintenance is great fun.

A couple of tips if you haven't already done this-

You'll need a 5/8" sparkplug socket and about 10" extension to reach down into the well each plug sits in (also, I'd suggest using some compressed air to blow any dirt out of the well before loosening the plug).

If your socket won't hold the plug while lowering, a good trick is to use appropriate sized rubber tubing (or in this example silicon tubing) to lower it in place and then start it threading with your fingers. Once it takes a bite, the plug will remain in place when you pull the tubing off. You don't want to cross thread one of these!

Be sure to use anti-seize on the threads an a little dielectric grease in the boot. Torque plugs to 10 lb/ft and have fun!

[sdmaro]

Definitely DIY worthy. I found a DIY garage that charged $25 an hour for full lift and power tools. Did all the fluid changes you listed along with my header install. Not hard at all... Just watch some youtube videos