I have been experiencing some grinding when I shift into 4th on my '83 308 Euro QV. How serious do you think this is? I've always had the grinding into second when cold but it does it into 4th when it's fairly warm. I just changed to the Redline gear lube and it did not help.
Is it pretty much all the time or just when you are really moving and shifting really fast? I have this 3 to 4 thing sometimes but only track days. If it were me I would just double clutch between 3rd and 4th and save a ton of $$$
Which redline product? They have one product specifically for troubled trannys (e.g. grinding gears).
Could well be the synchros. "Everybody" knows about 2nd, but 4th is the next weakest link in 308 transaxles. Many pepole don't know that and just baby 2nd; as a result, 4th goes first. Be especially deliberate shifting up to 4th when cold (or skip it) and while taking right hand corners.
It grinds when i shift quickly if I gingerly shift it does not. The receipt from the mechanic says Redline MT-90 Part#50304.
Consider discussing this product with your mechanic; it might, emphasis on might, save you from rebuilding your tranny to replace your synchros: http://www.redlineoil.com/products_gearlubricants.asp?pvID=87&prodID=61&subcatID=20
if you are changing the oil something that sometimes works is adding automatic transmission fluid.let it idle for 10 mins or so with your foot off the clutch.make sure the handbrake is on eh.while its idling push the gearlever gently to try and select 2,3,4,5 without using the clutch.do this very gently and dont use any force.DO NOT DRIVE WITH THIS OIL IN IT.IF YOU PUT THE OIL IN AND DONT DRAIN THE SAME DAY REMOVE KEYS AND ATTACH A NOTE TO THEM. drain oil and leave to drain for a couple of hours .refill with your oil and retry. nothing to lose and driveability to gain goodluck Tony
As the No Doubt guys says swap out the gear oil. Brian Crall (expert Ferrari tech) says Redline 75w-90 NS and for real troublesome shifting cars, then Redline MTL.
ATF has high detergent levels and is a great flush.we arent driving or stressing the gearbox.lets face it redline will have a thinner viscosity and a higher shear factor thats fine . but the gear(rotating mass) you are hoping to slow down to engage next has to be braked by a synchro ring or fibrecone. something is wrong.some oils are good at glazing up synchro rings and the area on the gear where the ring is designed to brake(generally the box is stripped,synchro and corresponding gear are lapped together and reassembled together.this deglazes the braked surface).sometimes these problems occur in something new.next thing that can happen is the synchro hub springs are weak so it takes less than normal effort to try and select gear before the gear has actually stopped rotating(grating,notchy).sometimes oil cant escape between the two.all these require strip down and examination of parts.ALL this requires is draining the oil /filling with atf /stationary selection of gears not 1st or reverse(gentle pressure not brute force)with the clutch out and brake on.the only thing contacting is the synchro.drain oil for 2/4 hrs and then refill with your low viscosity 75/90 oil. at worst you have flushed the gearbox.works good on noisey hydraulic lifters but thats another story.DO NOT DRIVE ON THIS OIL.FAST IDLE ONLY ONLY.NOT F1s. DECREASING FRICTION IS GREAT BUT YOU WANT IT WHERE SYNCHROS ARE AT WORK -somethings defy logic. Tony
REDLINE 75/ 90 NS But drop the pan and check shifting alignment as a 3rd to 4th problem sounds more like an ajustment issue. (Based on your description of problem) When dropping the pan watch out for for the little detent balls and springs.... Be careful not to loose them.
Hi Chris I thought I would add to this thread as I myself went through the exact symptoms you are experiencing. In my case I thought I would replace the gear oil to treat the gerabox but I used a fully synthetic 75w/90 gear oil. (Neo synthetic RHD) Within the first 15min of driving the gearbox began to crunch when engaging 2nd and 4th gears regardless of how gentle i pulled the lever. Quite unbelieveable really. I then drained the oil and replaced with a mineral based 75w/90 gear oil and the gearbox was back to normal. No crunching at all even on track when shifting as fast as my hand can pull the lever. As it turned out the fully synthetic oil was simply too slippery for the synchros to work. As for the Redline 75w/90 non slip lube I think this should do the job quite well. I have never used it myself but the product description is definitly in line with what is required. All the best
Now I'm really confused about gear lube. I bought MT-90 because it is described as 75-90 synthetic. http://www.redlineoil.com/products_gearlubricants.asp?pvID=74&prodID=57&subcatID=18 I've also been thinking it is adjustment issue I remember when I rented a 360 and couldn't even get it into 5th unless I pushed the shifter very hard to the right.
Redline has a confusing naming structure/convention for their products. When people say "75w90NS" they are talking about Redline's name for that product, which is a different product than Redline's "75w90" which is different than Redline's "MT-90" which is different from their "superlight shockproof" gear oil (even though it is a 75w90 **grade** of gear oil). So Redline products with identical or similar **grades** of oil have different **names**...but those names tend to fall along how people describe the grade of oil. Confusing.
