A/T, CVT Transmission - Howling Noise

A/T, CVT Transmission - Howling Noise

SI M 24 02 06

Automatic Transmission

January 2007

Technical Service

This Service Information bulletin supersedes S.I. M24 02 06 dated May 2006.

[NEW] designates changes to this revision

SUBJECT

CVT - Howling Noise from the Transmission

MODEL

R50 W10 with CVT up to 05/2005

SITUATION

The customer may complain about a howling type of noise coming from the CVT transmission, when the gear selector is placed in D, M, or S

position and the vehicle speed exceeds 5 mph.

The noise description may vary from "rattling" to "howling", depending on the degree of main bearing wear. The frequency of the noise increases

with the engine speed.

This noise is not present with the gear selector in N or P position and the vehicle at a standstill, with engine running at idle.

CAUSE

Excessive wear of the main ball bearing in the CVT transmission.

2002-2006 Mini Cooper (R50) L4-1.6L (W10) Page 264

CORRECTION

On a customer complaint basis only, replace the main CVT ball bearing together with the flange bolts, cover & oil pump O-rings and the plate

spring. For replacement instructions and tightening torques, refer to the [NEW] updated procedure below.

The special tools required to perform this repair: "M35 Socket" - P/N 83 30 0 494 914; "Bearing extractor kit" P/N 83 30 0 494 915; and "Bearing

driver" P/N 83 30 0 494 916 were shipped to all MINI dealers via the Automatic Tool Shipment Program (refer to SI M04 01 06).

[NEW] PROCEDURE

1. Remove front left wheel.

2. Remove left side wheel arch cover.

3. Remove thee bolts with clips securing the primary oil pump cover. Remove the primary cover.

4. Remove 4 M6x8 bolts (1) securing engine pitot chamber to oil pump drive.

Note on installation:

Install 4 new M6 bolts. Tightening

torque: 10 Nm.

5. Rotate the pitot chamber (1) until the flange bolt M6x55 (2), which secures engine pitot tube, can be visible.

6. Unscrew M6x55 bolt (2).

Note on installation:

Tightening torque: 10 Nm

2002-2006 Mini Cooper (R50) L4-1.6L (W10) Page 265

7. Rotate the pitot tube (1) 180锟斤拷 anticlockwise and remove it from the pitot chamber (2).

Note on installation:

Make sure to clean pitot chamber from any debris/oil residue prior to installation.

8. Remove 5 bolts M6x55 (1) securing the oil pump.

9. Remove inlet pressure tube (2).

Note on installation:

M6x55 bolts tightening torque: 10 Nm

10. Carefully remove oil pump (1) out

of the housing.

Note: you need to slightly pull transmission down (using a suitable prying bar) in order to safety clear a chassis member when removing pump out of

the housing.

11. Remove and discard two o-rings

(1). Install new o-rings (provided)

when reassembling.

2002-2006 Mini Cooper (R50) L4-1.6L (W10) Page 266

12. Discard plate spring (2).

13. Make clear marks on both M35X1.5 nut and primary shaft to identify their original position (both markings identified by an

arrow).

14. Using special socket (P/N 83 30 0 494 914) and an impact wrench with a torque capacity of 300 Nm, remove primary bearing nut (1).

Note on installation:

Replace plate spring.

Clean threads on both M35 nut and a

shaft (do not remove markings).

Make sure the primary pitot tube is not

twisted (points to the right).

Apply small amount of Loctite(R) 271 on

the threads and using an impact wrench

for a sufficient duration, tighten the nut

until marks are in line (+/- 5锟斤拷).

15. Using a small screwdriver, lever out seal from the primary bearing.

16. Remove the primary bearing using

"Bearing extractor kit" P/N 83 30 0 494 915.

2002-2006 Mini Cooper (R50) L4-1.6L (W10) Page 267

17. Clean primary bearing bore and shaft.

18. Clean sealant residue from threads in oil pump drive shaft and clean oil pump housing.

19. Drive new main ball bearing into position using "Bearing driver" P/N 83 30 0 494 916.94 916.

20. Reinstall oil pump.

21. Replace o-ring (1) for the main cover.

22. Reinstall all previously removed components.

23. Top-up transmission fluid with ESSO EZL 799.

PARTS INFORMATION

The parts MUST be replaced during the CVT main ball bearing replacement repair:

2002-2006 Mini Cooper (R50) L4-1.6L (W10) Page 268

The parts are to be removed and then re-used during the CVT main ball bearing replacement, and should be replaced ONLY if found to be defective

during visual inspection:

WARRANTY INFORMATION

Covered under the terms of the MINI New Vehicle Limited Warranty.