mel_t_vin

Interesting, usually it's the cold gearboxes that prove a little challenging to shift. Do you know what oil is in your gearbox and how long it has been there?

First thing I would do is drain the box and fill with Swepco 201 80w-90 gear oil [if you can get it]. It is, arguably, the best oil for the 4-speed 930 gearbox.

Since you have issues after things have warmed up [and stretched/expanded], I suspect some/most of your problem stems from improper alignment of the shifter linkage. Hopefully, your mechanic has access to the factory workshop manuals. If not, someone here may be able to post a .pdf of the proper alignment procedure.

TT Surgeon

An easy way to test the o rings is to wrap the IC joints in duct tape to seal them, test drive it, if it boosts you have your answer.

voodoo51

Allen
Chris
Thanks for your help!

How many liters of this oil should i buy?
And where could I find pdf of the proper alignment procedure?

mel_t_vin

Sergey, the 930 box holds about 3.7L of gear oil, so I'd say purchase 4L.

Remove the fill plug first, to make sure you don't drain the box and find out later that the fill plug is frozen in place. Remove the drain plug. Look for metal particles in oil. Dispose of oil. Replace drain plug. Fill, parked on level surface, to where oil is almost spilling out of fill hole. Replace fill plug. Have an enjoyable drive.

Regarding the shifter linkage alignment procedure, I know it's in the workshop manual. I would start a new thread here asking if anyone has a copy they would post online.

voodoo51

Now my gearbox is in the shop that specialized only in gearbox repaires. Because the shifter moves good and we think that the issue is inside the gearbox.

It is not easy to buy Swepco 201 80w-90 gear oil in Russia. Do you think that it is much better than original gear oil?

mel_t_vin

Sergey, hopefully that shop finds a quick and [relatively] easy fix. Fingers crossed...

Re: gear oil, everyone I know with a 4-speed 930 runs Swepco. I'm not even sure what the factory fill was in the mid- to late-eighties...probably some Shell product. When you say original gear oil, what brand/formulation are you referring to?

From my understanding of Porsche gear boxes, whereas the 5-sp G50 boxes [with Borg Warner single-cone syncros] were designed to use synthetic lubricants, the 4-sp 930 box was designed to use non-synthetic [less slippery] gear oil. Maybe a quick search here would provide additional information.

In any case, I think any high quality, non-synthetic, 80w-90 oil would work well.

voodoo51

Now I have list of spairparts that I have to buy:

93030113300 Guide Ring
93030233200 shaft sealing ring
99970144040 o-ring
99970143740 Rubber O-ring
99911318340 radial shaft seal (2 pieces)
99915203101 circlip sb 68 (2 pieces)
90011100100 circlip sp 62 (2 pieces)
93030119100 gasket
99911318540 shaft sealing ring
93030135100 gasket
93030230300 synchroniser ring 3rd/4th gear (2 pieces)
91130241120 shift sleeve
93030230100 synchroniser ring 1st/2nd gear (2 pieces)

I checked the prices on FVD, Pelican, Sunset Porsche and Autoatlanta.
Is it enough or should I try something more?


Also I have to start new several threads because my hot start problem is solved. But I have a lot of other issues. I don't give up thanks for your help!!!

As we took off the engine and gearbox should I check anything else (except of gearbox)?
The clutch has been already checked.

mel_t_vin

Sergey, as far as your parts list goes, I think you've covered the usual options.

So, what finally solved your hot start problem? And did you ever determine the root cause of your boost issue?

If you've dropped the engine/gearbox, now would be a good time to replace the thermostat o-ring [999 707 314 40] for your engine-mounted oil cooler. And this would be a good time to replace your spark plugs, as well.

voodoo51

Allen
Thank you!

Could you please answer how many thermostat o-rings [999 707 314 40] should I buy?
And what is the part number for spark plugs?

The hot start problem was caused by fuel metering unit (maybe I am mistaken in translating to English).

We didn't determine the root cause of boost issue. The shop will try to check it with all suggestions posted here (THANKS AGAIN!) in 1-2 months. When I will start to drive the car.

mel_t_vin

Sergey, only one thermostat o-ring is required. The stat sits on top of the engine, passenger [right] side, flywheel end. OE spark plugs are Bosch W3DPO...999.170.128.90 from the dealer. By the way, you'll need 6.

Yes, fuel metering unit...centerline, top of engine, to the left of the t-stat. If not functioning properly, that could certainly cause starting/running problems. Happy to hear you got that figured out.

voodoo51

Thank you Allen
Could you name the part number of the fuel metering unit?

mel_t_vin

Sergey, part number for the fuel distributor/metering unit for US-spec 930, '86-'89, is 930.110.923.00. I don't have the number for RoW-spec, which I suspect applies in your case. It's probably something like an 01 or 02.

Maybe someone else can chime in with the correct RoW number...

voodoo51

Thank you.
Correct part number for my car is 930 110 909 X. It's rather expensive (1.900 euro - FVD and 2.900 usd - Pelican)!
I spent in total 500 usd for problem diagnostics and repair of the fuel distributor.

mel_t_vin

Oh yeah...those fuel distributors are pricey parts.

I think we may have already discussed it in this thread, but, while you are in the process of putting everything back together, you may want to have someone test/calibrate your WUR [warm up regulator], 930.606.105.06. It is responsible for establishing/maintaining both cold and warm fuel system pressures. If it is not functioning properly, you will most certainly have driveability problems.

Klefroid

Get in contact with Mario from http://www.vankesselwebshop.nl/
Located in the Nederlands... he is way cheaper and same brands